Polarized semiconductor light emitting device

A light emitting device includes a light emitting diode (LED), a concentrator element, such as a compound parabolic concentrator, and a wavelength converting material, such as a phosphor. The concentrator element receives light from the LED and emits the light from an exit surface, which is smaller than the entrance surface. The wavelength converting material is, e.g., disposed over the exit surface. The radiance of the light emitting diode is preserved or increased despite the isotropic re-emitted light by the wavelength converting material. In one embodiment, the polarized light from a polarized LED is provided to a polarized optical system, such as a microdisplay. In another embodiment, the orthogonally polarized light from two polarized LEDs is combined, e.g., via a polarizing beamsplitter, and is provided to non-polarized optical system, such as a microdisplay. If desired, a concentrator element may be disposed between the beamsplitter and the microdisplay.

POWER LIGHT EMITTING DIODE AND METHOD WITH UNIFORM CURRENT DENSITY OPERATION

A light emitting diode device has a bulk gallium and nitrogen containing substrate with an active region. The device has a lateral dimension and a thick vertical dimension such that the geometric aspect ratio forms a volumetric diode that delivers a nearly uniform current density across the range of the lateral dimension. 1. A light emitting diode comprising:a bulk gallium and nitrogen containing substrate having a surface region; andan active region formed overlying the surface region;{'sup': 2', '2, 'wherein, the light emitting diode is configured to operate at a current density of the active region from 175 Amps/cmto 2,000 Amps/cm; and with an external quantum efficiency (EQE) of at least 50%.'}2. The light emitting diode of claim 1 , wherein the current density across the active region is substantially uniform at a current density from 175 Amps/cmto 2 claim 1 ,000 Amps/cm.3. The light emitting diode of claim 1 , wherein the emission intensity across the active region is within +/−20% at a current density from 175 Amps/cmto 2 claim 1 ,000 Amps/cm.4. The light emitting diode of claim 1 , wherein the emission intensity across the active region is within +/−10% at a current density at a current density from 175 Amps/cmto 2 claim 1 ,000 Amp s/cm.5. The light emitting diode of claim 1 , wherein the active region is characterized by a characteristic lateral dimension of at least 100 μm.6. The light emitting diode of claim 2 , wherein the light emitting diode is characterized by a vertical dimension and a characteristic lateral dimension claim 2 , wherein a ratio of the vertical dimension to the characteristic lateral dimension is from 0.05 to 10.7. The light emitting diode of claim 2 , wherein the ratio is from 0.1 to 5.8. The light emitting diode of claim 2 , wherein the ratio is from 0.2 to 2.9. The light emitting diode of claim 1 , wherein the light emitting diode is characterized by an aspect ratio defined by the ration of the vertical dimension and a ...

SEMICONDUCTOR LIGHT EMITTING DEVICES INCLUDING IN-PLANE LIGHT EMITTING LAYERS

A semiconductor light emitting device includes an in-plane active region that emits linearly-polarized light. An in-plane active region may include, for example, a {11 20} or {10 10} InGaN light emitting layer. In some embodiments, a polarizer oriented to pass light of a polarization of a majority of light emitted by the active region serves as a contact. In some embodiments, two active regions emitting the same or different colored light are separated by a polarizer oriented to pass light of a polarization of a majority of light emitted by the bottom active region, and to reflect light of a polarization of a majority of light emitted by the top active region. In some embodiments, a polarizer reflects light scattered by a wavelength converting layer.

III-Nitride Light Emitting Device with Reduced Strain Light Emitting Layer

In accordance with embodiments of the invention, strain is reduced in the light emitting layer of a III-nitride device by including a strain-relieved layer in the device. The surface on which the strain-relieved layer is grown is configured such that strain-relieved layer can expand laterally and at least partially relax. In some embodiments of the invention, the strain-relieved layer is grown over a textured semiconductor layer or a mask layer. In some embodiments of the invention, the strain-relieved layer is group of posts of semiconductor material.

Nitride semiconductor device with reduced polarization fields

A method for fabricating a light-emitting semiconductor device including a III-Nitride quantum well layer includes selecting a facet orientation of the quantum well layer to control a field strength of a piezoelectric field and/or a field strength of a spontaneous electric field in the quantum well layer, and growing the quantum well layer with the selected facet orientation. The facet orientation may be selected to reduce the magnitude of a piezoelectric field and/or the magnitude of a spontaneous electric field, for example. The facet orientation may also be selected to control or reduce the magnitude of the combined piezoelectric and spontaneous electric field strength.

LED LAMPS WITH IMPROVED QUALITY OF LIGHT

LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm. 130-. (canceled)31. A light-emitting system comprising:at least one LED device comprising an n-type region, a light-emitting active region, and a p-type region; and emitting a first radiation characterized by a first wavelength in a first range;at least one first wavelength conversion material optically coupled to the at least one LED device, wherein the at least one first wavelength conversion material converts a part of the first radiation to a second radiation characterized by a second wavelength in a second range from about 500 nm to about 600 nm; andat least one second wavelength conversion material optically coupled to the at least one LED device, wherein the at least one second wavelength conversion material converts a part of the first radiation to a third radiation characterized by a third wavelength in a third range from about 600 to about 700 nm,{'sup': '2', 'wherein the at least one LED device is characterized by an external quantum efficiency greater than 45% measured at a temperature of 25° C. and at a current density of 40 A/cm, and'}wherein a light spectrum emitted by the light-emitting system is characterized by a spectral power distribution (SPD) in which a fraction of the SPD in a fourth range from about 390 nm to about 430 nm is between 2% and 25%.32. The system of claim 31 , wherein the SPD is characterized by a correlated color temperature in a range from about 1900K to about 6500K.33. The system of claim 31 , wherein the SPD is characterized by a color rendering index CRI Ra higher than 75.34. The system of claim 31 , wherein the SPD is characterized by a chromatic distance to a Planckian locus having an absolute value that is lower than 0.01 in (u′v′) units.35. The system of claim 31 , further comprising some third ...

INDIUM GALLIUM NITRIDE LIGHT EMITTING DEVICES

InGaN-based light-emitting devices fabricated on an InGaN template layer are disclosed.

Methods for relaxation and transfer of strained layers and structures fabricated thereby

The present invention provides methods for forming at least partially relaxed strained material layers on a target substrate. The methods include forming islands of the strained material layer on an intermediate substrate, at least partially relaxing the strained material islands by a first heat treatment, and transferring the at least partially relaxed strained material islands to the target substrate. The at least partial relaxation is facilitated by the presence of low-viscosity or compliant layers adjacent to the strained material layer. The invention also provides semiconductor structures having an at least partially relaxed strained material layer, and semiconductor devices fabricated using an at least partially relaxed strained material layer.

Light emitting diodes with improved light extraction efficiency

Light emitting devices with improved light extraction efficiency are provided. The light emitting devices have a stack of layers including semiconductor layers comprising an active region. The stack is bonded to a transparent optical element having a refractive index for light emitted by the active region preferably greater than about 1.5, more preferably greater than about 1.8. A method of bonding a transparent optical element (e.g., a lens or an optical concentrator) to a light emitting device comprising an active region includes elevating a temperature of the optical element and the stack and applying a pressure to press the optical element and the light emitting device together. A block of optical element material may be bonded to the light emitting device and then shaped into an optical element. Bonding a high refractive index optical element to a light emitting device improves the light extraction efficiency of the light emitting device by reducing loss due to total internal reflection. Advantageously, this improvement can be achieved without the use of an encapsulant.

A1InGaP LED having reduced temperature dependence

To increase the lattice constant of AlInGaP LED layers to greater than the lattice constant of GaAs for reduced temperature sensitivity, an engineered growth layer is formed over a substrate, where the growth layer has a lattice constant equal to or approximately equal to that of the desired AlInGaP layers. In one embodiment, a graded InGaAs or InGaP layer is grown over a GaAs substrate. The amount of indium is increased during growth of the layer such that the final lattice constant is equal to that of the desired AlInGaP active layer. In another embodiment, a very thin InGaP, InGaAs, or AlInGaP layer is grown on a GaAs substrate, where the InGaP, InGaAs, or AlInGaP layer is strained (compressed). The InGaP, InGaAs, or AlInGaP thin layer is then delaminated from the GaAs and relaxed, causing the lattice constant of the thin layer to increase to the lattice constant of the desired overlying AlInGaP LED layers. The LED layers are then grown over the thin InGaP, InGaAs, or AlInGaP layer.

Wavelength-converted semiconductor light emitting device

A material such as a phosphor is optically coupled to a semiconductor structure including a light emitting region disposed between an n-type region and a p-type region, in order to efficiently extract light from the light emitting region into the phosphor. The phosphor may be phosphor grains in direct contact with a surface of the semiconductor structure, or a ceramic phosphor bonded to the semiconductor structure, or to a thin nucleation structure on which the semiconductor structure may be grown. The phosphor is preferably highly absorbent and highly efficient. When the semiconductor structure emits light into such a highly efficient, highly absorbent phosphor, the phosphor may efficiently extract light from the structure, reducing the optical losses present in prior art devices.

LED lamps with improved quality of light

LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm.

Illumination sources with thermally-isolated electronics

An lighting source includes a driver for outputting electrical power in response to external electrical power, wherein the driver generates heat in response thereto, a lamp coupled to the driver, for outputting light in response to the electrical power, wherein the lamp generates heat in response thereto, a first heat sink physically coupled to the driver for receiving and dissipating heat there from, a second heat sink physically coupled to the light for receiving heat and dissipating heat there from, and an insulating portion disposed between the first heat sink and the second heat sink, wherein the insulating portion is configured to inhibit heat from the lamp from being transferred to the driver.

CONTACT FOR A SEMICONDUCTOR LIGHT EMITTING DEVICE

An AlGaInP light emitting device is formed as a thin, flip chip device. The device includes a semiconductor structure comprising an AlGaInP light emitting layer disposed between an n-type region and a p-type region. N- and p-contacts electrically connected to the n- and p-type regions are both formed on the same side of the semiconductor structure. The semiconductor structure is connected to the mount via the contacts. The growth substrate is removed from the semiconductor structure and the thick transparent substrate is omitted, such that the total thickness of semiconductor layers in the device is less than 15 m in some embodiments, less than 10 m in some embodiments. The top side of the semiconductor structure may be textured.

Grown photonic crystals in semiconductor light emitting devices

A photonic crystal is grown within a semiconductor structure, such as a III-nitride structure, which includes a light emitting region disposed between an n-type region and a p-type region. The photonic crystal may be multiple regions of semiconductor material separated by a material having a different refractive index than the semiconductor material. For example, the photonic crystal may be posts of semiconductor material grown in the structure and separated by air gaps or regions of masking material. Growing the photonic crystal, rather than etching a photonic crystal into an already-grown semiconductor layer, avoids damage caused by etching which may reduce efficiency, and provides uninterrupted, planar surfaces on which to form electric contacts.

III-nitride light emitting device with reduced strain light emitting layer

In accordance with embodiments of the invention, strain is reduced in the light emitting layer of a III-nitride device by including a strain-relieved layer in the device. The surface on which the strain-relieved layer is grown is configured such that strain-relieved layer can expand laterally and at least partially relax. In some embodiments of the invention, the strain-relieved layer is grown over a textured semiconductor layer or a mask layer. In some embodiments of the invention, the strain-relieved layer is group of posts of semiconductor material.

Luminescent ceramic for a light emitting device

A semiconductor light emitting device comprising a light emitting layer disposed between an n-type region and a p-type region is combined with a ceramic layer which is disposed in a path of light emitted by the light emitting layer. The ceramic layer is composed of or includes a wavelength converting material such as a phosphor. Luminescent ceramic layers according to embodiments of the invention may be more robust and less sensitive to temperature than prior art phosphor layers. In addition, luminescent ceramics may exhibit less scattering and may therefore increase the conversion efficiency over prior art phosphor layers.

LED LAMPS WITH IMPROVED QUALITY OF LIGHT

LED lamps having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm. 1. An LED lamp comprising an LED device , wherein the LED lamp is characterized by a luminous flux of more than 500 lm , and a spectral power distribution (SPD) in which more than 2% of the power is emitted within a wavelength range from about 390 nm to about 430 nm.2. The lamp of claim 1 , wherein the luminous flux is at least 1500 lm.3. The lamp of claim 1 , wherein the lamp comprises an MR16 form factor.4. The lamp of claim 1 , wherein the lamp comprises a PAR30 lamp form factor.5. The lamp of claim 1 , wherein the LED device comprises at least one violet-emitting LED.6. The lamp of claim 5 , wherein the at least one violet-emitting LED is configured to emit more than 200W/cmat a current density of 200 A/cmat a junction temperature of 100° C. or greater.7. The lamp of claim 5 , wherein the at least one violet-emitting LED pumps at least a blue phosphor or at least one cyan phosphor.8. The lamp of claim 5 , wherein the LED device comprises at least one LED configured to emit at a wavelength other than a wavelength emitted by the at least one violet-emitting LED.9. The lamp of claim 1 , wherein a short wavelength SPD discrepancy (SWSD) for a source with a correlated color temperature (CCT) in a range 2500K to 7000K is less than 35%.10. The lamp of claim 1 , wherein a violet leak of the light source is configured to achieve a particular CIE whiteness value.11. The lamp of claim 10 , wherein the violet leak is such that a CIE whiteness of a high-whiteness reference sample illuminated by the lamp is within minus 20 points and plus 40 points of a CIE whiteness of the same sample under illumination by a CIE reference illuminant of same CCT (respectively a blackbody radiator if CCT<5000K or a D illuminant if CCT>5000K).12. The lamp of claim 10 , ...

Semiconductor Light Emitting Device Including Porous Layer

A light emitting device includes a semiconductor structure having a light emitting layer disposed between an n-type region and a p-type region. A porous region is disposed between the light emitting layer and a contact electrically connected to one of the n-type region and the p-type region. The porous region scatters light away from the absorbing contact, which may improve light extraction from the device. In some embodiments the porous region is an n-type semiconductor material such as GaN or GaP.

Selective filtering of wavelength-converted semiconductor light emitting devices

A light emitting device includes a semiconductor light emitting device chip having a top surface and a side surface, a wavelength-converting material overlying at least a portion of the top surface and the side surface of the chip, and a filter material overlying the wavelength-converting material. The chip is capable of emitting light of a first wavelength, the wavelength-converting material is capable of absorbing light of the first wavelength and emitting light of a second wavelength, and the filter material is capable of absorbing light of the first wavelength. In other embodiments, a light emitting device includes a filter material capable of reflecting light of a first wavelength and transmitting light of a second wavelength.

LUMINESCENT CERAMIC FOR A LIGHT EMITTING DEVICE

A semiconductor light emitting device comprising a light emitting layer disposed between an n-type region and a p-type region is combined with a ceramic layer which is disposed in a path of light emitted by the light emitting layer. The ceramic layer is composed of or includes a wavelength converting material such as a phosphor. Luminescent ceramic layers according to embodiments of the invention may be more robust and less sensitive to temperature than prior art phosphor layers. In addition, luminescent ceramics may exhibit less scattering and may therefore increase the conversion efficiency over prior art phosphor layers.

Semiconductor light emitting device and method

A light-emitting device includes: a semiconductor structure formed on one side of a substrate, the semiconductor structure having a plurality of semiconductor layers and an active region within the layers; and first and second conductive electrodes contacting respectively different semiconductor layers of the structure; the substrate comprising a material having a refractive index n>2.0 and light absorption coefficient alpha, at the emission wavelength of the active region, of alpha>3 cm^-1. In a preferred embodiment, the substrate material has a refractive index n>2.3, and the light absorption coefficient, alpha, of the substrate material is alpha<1 CM^-1.

Method and system for dicing substrates containing gallium and nitrogen material

The present disclosure relates generally to semiconductor techniques. More specifically, embodiments of the present disclosure provide methods for efficiently dicing substrates containing gallium and nitrogen material. Additionally the present disclosure provide techniques resulting in a optical device comprising a substrate having three or more corners, where at least one of the corners is defined by a dislocation bundle characterized by a diameter of less than 100 microns, the gallium and nitrogen containing substrate having a predefined portion free from dislocation bundle centers, an active region containing one or more active layers, the active region being positioned within the predefined region; and a conductive region formed within the predefined region.

CIRCADIAN-FRIENDLY LED LIGHT SOURCES

Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80. 1. A method of using a lighting system to emit emitted light having a relatively high illuminance but a relatively low circadian stimulation , said light system having at least one solid-state lighting emitter , and at least a first and second additional light emitters for cooperating with said lighting emitter such that said emitted light is white light , said method comprising:applying power to said lighting system thereby causing at least said light emitter and said first and second additional light emitters to emit said emitted light having a certain correlated color temperature (CCT), the lighting system being configured to produce an illuminance of about 50 lux to about 5000 lux, and a circadian stimulation no greater than about 50% of a reference circadian stimulation of a reference illuminant configured to produce an illuminance essentially the same as said predetermined illuminance and a CCT the same as said certain CCT.2. The method of claim 1 , wherein said circadian stimulation is no greater than about 20% of said reference circadian stimulation.3. The method of claim 1 , wherein the light emitter comprises at least one light-emitting diode or one laser diode emitting having a peak wavelength in a range 400-430 nm claim 1 , said first additional light emitter has an emission spectrum having a peak between 500 nm and 550 nm claim 1 , and said second additional light emitter has an emission spectrum having a peak between 600 nm and ...

SERIES CONNECTED FLIP CHIP LEDS WITH GROWTH SUBSTRATE REMOVED

LED layers are grown over a sapphire substrate. Individual flip chip LEDs are formed by trenching or masked ion implantation. Modules containing a plurality of LEDs are diced and mounted on a submount wafer. A submount metal pattern or a metal pattern formed on the LEDs connects the LEDs in a module in series. The growth substrate is then removed, such as by laser lift-off. A semi-insulating layer is formed, prior to or after mounting, that mechanically connects the LEDs together. The semi-insulating layer may be formed by ion implantation of a layer between the substrate and the LED layers. PEC etching of the semi-insulating layer, exposed after substrate removal, may be performed by biasing the semi-insulating layer. The submount is then diced to create LED modules containing series-connected LEDs. 112-. (canceled)13. A module containing a plurality of light emitting devices (LEDs) , the module comprising:electrically isolated individual LEDs, each LED including an N-layer, an active layer, and a P-layer;a semi-insulating isolation layer common to the individual LEDs that mechanically couples together the individual LEDs; anda metal pattern that connects the individual LEDs, at least two of the LEDs being connected together in series.14. The module of wherein the individual LEDs are separated by trenches formed at least through the P-layer and active layer.15. The module of wherein the individual LEDs are separated by semi-insulating isolation regions formed by ion implantation.16. The module of wherein the semi-insulating layer includes a semiconductor layer with defects in a crystalline structure of the semiconductor layer.17. The module of wherein the semi-insulating layer includes an ion-implanted semiconductor layer.18. The module of including a submount that supports the module of individual LEDs.19. The module of wherein the submount includes at least a portion of the metal pattern that connects the individual LEDs.20. The module of wherein the metal ...

Multi-part heat exchanger for LED lamps

Multi-part heat exchangers for hot/cold temperature domain isolation in LED lamps are disclosed.

Power light emitting diode and method with uniform current density operation

A light emitting diode device has a bulk gallium and nitrogen containing substrate with an active region. The device has a lateral dimension and a thick vertical dimension such that the geometric aspect ratio forms a volumetric diode that delivers a nearly uniform current density across the range of the lateral dimension.

Resonant cavity III-nitride light emitting devices fabricated by growth substrate removal

A semiconductor light emitting device includes an n-type region, a p-type region, and light emitting region disposed between the n- and p-type regions. The n-type, p-type, and light emitting regions form a cavity having a top surface and a bottom surface. Both the top surface and the bottom surface of the cavity may have a rough surface. For example, the surface may have a plurality of peaks separated by a plurality of valleys. In some embodiments, the thickness of the cavity is kept constant by incorporating an etch-stop layer into the device, then thinning the layers of the device by a process that terminates on the etch-stop layer.

COMPLIANT BONDING STRUCTURES FOR SEMICONDUCTOR DEVICES

A compliant bonding structure is disposed between a semiconductor light emitting device and a mount. When the semiconductor light emitting device is attached to the mount, for example by providing pressure, heat, and/or ultrasonic energy to the semiconductor light emitting device, the compliant bonding structure collapses to partially fill a space between the semiconductor light emitting device and the mount. In some embodiments, the compliant bonding structure is plurality of metal bumps that undergo plastic deformation during bonding. In some embodiments, the compliant bonding structure is a porous metal layer.

Grown Photonic Crystals in Semiconductor Light Emitting Devices

A photonic crystal is grown within a semiconductor structure, such as a III-nitride structure, which includes a light emitting region disposed between an n-type region and a p-type region. The photonic crystal may be multiple regions of semiconductor material separated by a material having a different refractive index than the semiconductor material. For example, the photonic crystal may be posts of semiconductor material grown in the structure and separated by air gaps or regions of masking material. Growing the photonic crystal, rather than etching a photonic crystal into an already-grown semiconductor layer, avoids damage caused by etching which may reduce efficiency, and provides uninterrupted, planar surfaces on which to form electric contacts. 131-. (canceled)32. A device comprising:a semiconductor structure comprising a light emitting layer configured to emit light of wavelength λ, the light emitting layer being disposed between an n-type region and a p-type region, the semiconductor structure having a top surface and a bottom surface; and a plurality of regions of semiconductor material having a first refractive index; and', 'a plurality of regions of a material having a second refractive index, wherein the second refractive index is different from the first refractive index;', 'wherein the regions of material having a second refractive index are disposed between the regions of semiconductor material in an array, and each region of material having a second refractive index is located less than 5λ from a nearest neighbor region of material having a second refractive index;, 'a photonic crystal disposed within the semiconductor structure, the photonic crystal comprisingwherein the light emitting layer is disposed within the photonic crystal; andwherein the top surface and the bottom surface of the semiconductor structure are uninterrupted by the photonic crystal.33. The device of wherein the light emitting layer is a III-nitride layer.34. The device of wherein ...

Photonic crystal light emitting device

A photonic crystal structure is formed in an n-type region of a III-nitride semiconductor structure including an active region sandwiched between an n-type region and a p-type region. A reflector is formed on a surface of the p-type region opposite the active region. In some embodiments, the growth substrate on which the n-type region, active region, and p-type region are grown is removed, in order to facilitate forming the photonic crystal in an an-type region of the device, and to facilitate forming the reflector on a surface of the p-type region underlying the photonic crystal. The photonic crystal and reflector form a resonant cavity, which may allow control of light emitted by the active region.

Indium-gallium-nitride structures and devices

InGaN layers characterized by an in-plane lattice constant within a range from 3.19 to 3.50 Å are disclosed. The InGaN layers are grown by coalescing InGaN grown on a plurality of GaN regions. The InGaN layers can be used to fabricate optical and electronic devices for use in light sources for illumination and display applications.

III-NITRIDE LIGHT EMITTING DEVICE WITH DOUBLE HETEROSTRUCTURE LIGHT EMMITTING REGION

A III-nitride light emitting layer is disposed between an n-type region and a p-type region in a double heterostructure. At least a portion of the III-nitride light emitting layer has a graded composition.

Array of Light Emitting Devices to Produce a White Light Source

A device is provided with an array of a plurality of phosphor converted light emitting devices (LEDs) that produce broad spectrum light. The phosphor converted LEDs may produce light with different correlated color temperature (CCT) and are covered with an optical element that assists in mixing the light from the LEDs to produce a desired correlated color temperature. The phosphor converted LEDs may also be combined in an array with color LEDs. The color LEDs may be controlled to vary their brightness such that light with an approximately continuous broad spectrum is produced. By controlling the brightness of the color LEDs, light can be produced with a fixed brightness over a large range of white points with a high color rendering quality.

Luminescent ceramic for a light emitting device

A semiconductor light emitting device comprising a light emitting layer disposed between an n-type region and a p-type region is combined with a ceramic layer which is disposed in a path of light emitted by the light emitting layer. The ceramic layer is composed of or includes a wavelength converting material such as a phosphor. Luminescent ceramic layers according to embodiments of the invention may be more robust and less sensitive to temperature than prior art phosphor layers. In addition, luminescent ceramics may exhibit less scattering and may therefore increase the conversion efficiency over prior art phosphor layers.

Using electrophoresis to produce a conformally coated phosphor-converted light emitting semiconductor

Presented is a method of conformally coating a light emitting semiconductor structure with a phosphor layer to produce a substantially uniform white light. A light emitting semiconductor structure is coupled to a submount, a first bias voltage is applied to the submount, and a second bias voltage is applied to a solution of charged phosphor particles. The charged phosphor particles deposit on the conductive surfaces of the light emitting semiconductor structure. If the light emitting semiconductor structure includes a nonconductive substrate, the light emitting semiconductor structure is coated with an electroconductive material to induce phosphor deposition. The electrophoretic deposition of the phosphor particles creates a phosphor layer of uniform thickness that produces uniform white light without colored rings.

Wavelength-Converted Semiconductor Light Emitting Device

A material such as a phosphor is optically coupled to a semiconductor structure including a light emitting region disposed between an n-type region and a p-type region, in order to efficiently extract light from the light emitting region into the phosphor. The phosphor may be phosphor grains in direct contact with a surface of the semiconductor structure, or a ceramic phosphor bonded to the semiconductor structure, or to a thin nucleation structure on which the semiconductor structure may be grown. The phosphor is preferably highly absorbent and highly efficient. When the semiconductor structure emits light into such a highly efficient, highly absorbent phosphor, the phosphor may efficiently extract light from the structure, reducing the optical losses present in prior art devices.

LIGHT EMITTING DEVICES WITH IMPROVED LIGHT EXTRACTION EFFICIENCY

A device includes a light emitting structure and a wavelength conversion member comprising a semiconductor. The light emitting structure is bonded to the wavelength conversion member. In some embodiments, the light emitting structure is bonded to the wavelength conversion member with an inorganic bonding material. In some embodiments, the light emitting structure is bonded to the wavelength conversion member with a bonding material having an index of refraction greater than 1.5.

METHODS OF FORMING RELAXED LAYERS OF SEMICONDUCTOR MATERIALS, SEMICONDUCTOR STRUCTURES, DEVICES AND ENGINEERED SUBSTRATES INCLUDING SAME

Methods of fabricating relaxed layers of semiconductor materials include forming structures of a semiconductor material overlying a layer of a compliant material, and subsequently altering a viscosity of the compliant material to reduce strain within the semiconductor material. The compliant material may be reflowed during deposition of a second layer of semiconductor material. The compliant material may be selected so that, as the second layer of semiconductor material is deposited, a viscosity of the compliant material is altered imparting relaxation of the structures. In some embodiments, the layer of semiconductor material may comprise a III-V type semiconductor material, such as, for example, indium gallium nitride. Methods of fabricating semiconductor structures and devices are also disclosed. Novel intermediate structures are formed during such methods. Engineered substrates include a plurality of structures comprising a semiconductor material disposed on a layer of material exhibiting ...

Wavelength-converted semiconductor light emitting device

A material such as a phosphor is optically coupled to a semiconductor structure including a light emitting region disposed between an n-type region and a p-type region, in order to efficiently extract light from the light emitting region into the phosphor. The phosphor may be phosphor grains in direct contact with a surface of the semiconductor structure, or a ceramic phosphor bonded to the semiconductor structure, or to a thin nucleation structure on which the semiconductor structure may be grown. The phosphor is preferably highly absorbent and highly efficient. When the semiconductor structure emits light into such a highly efficient, highly absorbent phosphor, the phosphor may efficiently extract light from the structure, reducing the optical losses present in prior art devices.

METHOD OF FORMING A COMPOSITE SUBSTRATE AND GROWING A III-V LIGHT EMITTING DEVICE OVER THE COMPOSITE SUBSTRATE

A method according to embodiments of the invention includes providing a substrate comprising a host and a seed layer bonded to the host. The seed layer comprises a plurality of regions. A semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region is grown on the substrate. A top surface of a semiconductor layer grown on the seed layer has a lateral extent greater than each of the plurality of seed layer regions.

Wavelength-converted semiconductor light emitting device

Embodiments of the invention include a light emitting structure comprising a light emitting layer. A first luminescent material comprising a phosphor is disposed in a path of light emitted by the light emitting layer. A second luminescent material comprising a semiconductor is also disposed in a path of light emitted by the light emitting layer. The second luminescent material is configured to absorb light emitted by the light emitting layer and emit light of a different wavelength. In some embodiments, one of the first and second luminescent materials may be bonded to the semiconductor structure.

Compliant bonding structures for semiconductor devices

A light emitting device includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region, a metal p-contact disposed on the p-type region, and a metal n-contact disposed on the n-type region. The metal p-contact and the metal n-contact are both formed on the same side of the semiconductor structure. The light emitting device is connected to a mount by a bonding structure. The bonding structure includes a plurality of metal regions separated by gaps and a metal structure disposed between the light emitting device and the mount proximate to an edge of the light emitting device. The metal structure is configured such that during bonding, the metal structure forms a continuous seal between the light emitting device and the mount.

Mount for a semiconductor light emitting device

A mount for a semiconductor device includes a carrier, at least two metal leads disposed on a bottom surface of the carrier, and a cavity extending through a thickness of the carrier to expose a portion of the top surfaces of the metal leads. A semiconductor light emitting device is positioned in the cavity and is electrically and physically connected to the metal leads. The carrier may be, for example, silicon, and the leads may be multilayer structures, for example a thin gold layer connected to a thick copper layer.

LED LAMPS WITH IMPROVED QUALITY OF LIGHT

LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm. 1. An illumination system comprising:at least one LED device configured in a housing structure, wherein the at least one LED device comprises an n-type region, a light-emitting active region, and a p-type region;a wavelength conversion material optically coupled to the at least one LED device; anda power source electrically coupled to the at least one LED device; wherein,{'sup': '2', 'the at least one LED device is characterized by an external quantum efficiency greater than 45% measured at an ambient temperature of 25° C. and at a current density of 40 A/cm; and'}light emitted by an interaction of electromagnetic radiation emitted from the at least one LED device and from the wavelength conversion material is characterized by a spectral power distribution (SPD) in which from 1% to 4% of the power in the SPD is emitted within a short-wavelength range from about 390 nm to about 430 nm.2. The illumination system of claim 1 , wherein the LED device comprises a gallium and nitride-containing substrate.3. The illumination system of claim 1 , wherein the at least one LED is configured to emit electromagnetic radiation within the short-wavelength range from about 390 nm to about 430 nm.4. The illumination system of claim 1 , wherein claim 1 ,the wavelength conversion material comprises a blue phosphor and a green phosphor; andthe green phosphor is configured to absorb electromagnetic radiation emitted by the blue phosphor.5. The illumination system of claim 1 , comprising a second LED device claim 1 , wherein the second LED device is configured to emit electromagnetic radiation within a blue wavelength range claim 1 , within a green wavelength range claim 1 , or within a red wavelength range.6. The illumination system of claim 1 , comprising one ...

LED including photonic crystal structure

A photonic crystal light emitting diode ("PXLED") is provided. The PXLED includes a periodic structure, such as a lattice of holes, formed in the semiconductor layers of an LED. The parameters of the periodic structure are such that the energy of the photons, emitted by the PXLED, lies close to a band edge of the band structure of the periodic structure. Metal electrode layers have a strong influence on the efficiency of the PXLEDs. Also, PXLEDs formed from GaN have a low surface recombination velocity and hence a high efficiency. The PXLEDs are formed with novel fabrication techniques, such as the epitaxial lateral overgrowth technique over a patterned masking layer, yielding semiconductor layers with low defect density. Inverting the PXLED to expose the pattern of the masking layer or using the Talbot effect to create an aligned second patterned masking layer allows the formation of PXLEDs with low defect density.

Selective filtering of wavelength-converted semiconductor light emitting devices

A structure includes a semiconductor light emitting device including a light emitting layer disposed between an n-type region and a p-type region. The light emitting layer emits first light of a first peak wavelength. A wavelength-converting material that absorbs the first light and emits second light of a second peak wavelength is disposed in the path of the first light. A filter material that transmits a portion of the first light and absorbs or reflects a portion of the first light is disposed over the wavelength-converting material.

AllnGaP LED having reduced temperature dependence

To increase the lattice constant of AlInGaP LED layers to greater than the lattice constant of GaAs for reduced temperature sensitivity, an engineered growth layer is formed over a substrate, where the growth layer has a lattice constant equal to or approximately equal to that of the desired AlInGaP layers. In one embodiment, a graded InGaAs or InGaP layer is grown over a GaAs substrate. The amount of indium is increased during growth of the layer such that the final lattice constant is equal to that of the desired AlInGaP active layer. In another embodiment, a very thin InGaP, InGaAs, or AlInGaP layer is grown on a GaAs substrate, where the InGaP, InGaAs, or AlInGaP layer is strained (compressed). The InGaP, InGaAs, or AlInGaP thin layer is then delaminated from the GaAs and relaxed, causing the lattice constant of the thin layer to increase to the lattice constant of the desired overlying AlInGaP LED layers. The LED layers are then grown over the thin InGaP, InGaAs, or AlInGaP layer.

Heterostructures for III-nitride light emitting devices

Heterostructure designs are disclosed that may increase the number of charge carriers available in the quantum well layers of the active region of III-nitride light emitting devices such as light emitting diodes. In a first embodiment, a reservoir layer is included with a barrier layer and quantum well layer in the active region of a light emitting device. In some embodiments, the reservoir layer is thicker than the barrier layer and quantum well layer, and has a greater indium composition than the barrier layer and a smaller indium composition than the quantum well layer. In some embodiments, the reservoir layer is graded. In a second embodiment, the active region of a light emitting device is a superlattice of alternating quantum well layers and barrier layers. In some embodiments, the barrier layers are thin such that charge carriers can tunnel between quantum well layers through a barrier layer.

III-V light emitting device including a light extracting structure

Embodiments of the invention include a substrate comprising a host and a seed layer bonded to the host, and a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region grown over the seed layer. A variation in index of refraction in a direction perpendicular to a growth direction of the semiconductor structure is disposed between the host and the light emitting layer.

III-Phosphide and III-Arsenide flip chip light-emitting devices

A light-emitting semiconductor device includes a stack of layers including an active region. The active region includes a semiconductor selected from the group consisting of III-Phosphides, III-Arsenides, and alloys thereof. A superstrate substantially transparent to light emitted by the active region is disposed on a first side of the stack. First and second electrical contacts electrically coupled to apply a voltage across the active region are disposed on a second side of the stack opposite to the first side. In some embodiments, a larger fraction of light emitted by the active region exits the stack through the first side than through the second side. Consequently, the light-emitting semiconductor device may be advantageously mounted as a flip chip to a submount, for example.

Reverse polarization light emitting region for a semiconductor light emitting device

A semiconductor light emitting device includes a light emitting layer disposed between an n-type region and a p-type region. The light emitting layer may be a wurtzite III-nitride layer with a thickness of at least 50 angstroms. The light emitting layer may have a polarization reversed from a conventional wurtzite III-nitride layer, such that across an interface between the light emitting layer and the p-type region, the wurtzite c-axis points toward the light emitting layer. Such an orientation of the c-axis may create a negative sheet charge at an interface within or at the edge of the p-type region, providing a barrier to charge carriers in the light emitting layer.

Semiconductor light emitting device growing active layer on textured surface

In accordance with embodiments of the invention, at least partial strain relief in a light emitting layer of a III-nitride light emitting device is provided by configuring the surface on which at least one layer of the device grows such that the layer expands laterally and thus at least partially relaxes. This layer is referred to as the strain-relieved layer. In some embodiments, the light emitting layer itself is the strain-relieved layer, meaning that the light emitting layer is grown on a surface that allows the light emitting layer to expand laterally to relieve strain. In some embodiments, a layer grown before the light emitting layer is the strain-relieved layer. In a first group of embodiments, the strain-relieved layer is grown on a textured surface.

Grown photonic crystals in semiconductor light emitting devices

A photonic crystal is grown within a semiconductor structure, such as a III-nitride structure, which includes a light emitting region disposed between an n-type region and a p-type region. The photonic crystal may be multiple regions of semiconductor material separated by a material having a different refractive index than the semiconductor material. For example, the photonic crystal may be posts of semiconductor material grown in the structure and separated by air gaps or regions of masking material. Growing the photonic crystal, rather than etching a photonic crystal into an already-grown semiconductor layer, avoids damage caused by etching which may reduce efficiency, and provides uninterrupted, planar surfaces on which to form electric contacts.

LED lamps with improved quality of light

LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm.

POWER LIGHT EMITTING DIODE AND METHOD WITH UNIFORM CURRENT DENSITY OPERATION

A light emitting diode device has a bulk gallium and nitrogen containing substrate with an active region. The device has a lateral dimension and a thick vertical dimension such that the geometric aspect ratio forms a volumetric diode that delivers a nearly uniform current density across the range of the lateral dimension. 1. A light emitting device comprising:a bulk III-Nitride substrate; and one n-doped layer;', 'one active region configured to emit light having a peak wavelength of 385-480 nm; and', 'one p-doped layer; and, 'epitaxial layers grown over said substrate comprising at least,'}{'sup': 17', '3', '−1, 'wherein said substrate has a dopant concentration above 10cmand an absorption coefficient for said light no greater than 3 cm.'}2. The light emitting device of claim 1 , wherein said absorption coefficient is no greater than 2 cm.3. The light emitting device of claim 2 , wherein said absorption coefficient is no greater than 0.5 cm.4. The light emitting device of claim 2 , wherein said substrate has a threading dislocation density <10cm.5. The light emitting device of claim 4 , wherein said substrate has a stacking fault density <10cm.6. The light emitting device of claim 5 , wherein said substrate has a length greater than about 5 millimeters claim 5 , and a Wurtzite structure claim 5 , which is substantially free of other crystal structures.7. The light emitting device of claim 1 , wherein said substrate and said epitaxial layers have a dislocation density <10cm.8. The light emitting device of claim 7 , wherein said substrate and said epitaxial layers have a dislocation density <10cm.9. The light emitting device of claim 1 , wherein said light emitting device has an external quantum efficiency of at least 50% at a power density of 2 watts/mmand a junction temperature of 100C°.10. The light emitting device of claim 1 , further comprising a phosphor disposed over said active region to absorb at least a portion of said light.11. The light emitting device of ...

Low profile side emitting LED

Low profile, side-emitting LEDs are described, where all light is efficiently emitted within a relatively narrow angle generally parallel to the surface of the light-generating active layer. The LEDs enable the creation of very thin backlights for backlighting an LCD. In one embodiment, the LED is a flip chip with the n and p electrodes on the same side of the LED, and the LED is mounted electrode-side down on a submount. A reflector is provided on the top surface of the LED so that light impinging on the reflector is reflected back toward the active layer and eventually exits through a side surface of the LED. A waveguide layer and/or one or more phosphors layers are deposed between the semiconductor layers and the reflector for increasing the side emission area for increased efficiency. Side-emitting LEDs with a thickness of between 0.2-0.4 mm can be created.

Series connected flip chip LEDs with growth substrate removed

LED layers are grown over a sapphire substrate. Individual flip chip LEDs are formed by trenching or masked ion implantation. Modules containing a plurality of LEDs are diced and mounted on a submount wafer. A submount metal pattern or a metal pattern formed on the LEDs connects the LEDs in a module in series. The growth substrate is then removed, such as by laser lift-off. A semi-insulating layer is formed, prior to or after mounting, that mechanically connects the LEDs together. The semi-insulating layer may be formed by ion implantation of a layer between the substrate and the LED layers. PEC etching of the semi-insulating layer, exposed after substrate removal, may be performed by biasing the semi-insulating layer. The submount is then diced to create LED modules containing series-connected LEDs.

POWER LIGHT EMITTING DIODE AND METHOD WITH UNIFORM CURRENT DENSITY OPERATION

A light emitting diode device has a bulk gallium and nitrogen containing substrate with an active region. The device has a lateral dimension and a thick vertical dimension such that the geometric aspect ratio forms a volumetric diode that delivers a nearly uniform current density across the range of the lateral dimension. 120-. (canceled)21. A semiconductor device made by the steps comprising:(a) disposing epitaxial layers on a substrate, said substrate comprising bulk III-Nitride with n-doping above 1E17 cm-3, said epitaxial layers comprising at least one doped epi layer;(b) disposing a second contact at least partially on said doped epi layer;(c) treating a surface of said substrate by dry etching to define a n-GaN surface; and(d) disposing an n-contact directly on said n-GaN surface, said n-contact being ohmic.22. The device of claim 21 , wherein steps (a) and (b) are performed before steps (c) and (d).23. The device of claim 22 , wherein said dry etching also defines at least one mesa on said substrate.24. The device of claim 21 , wherein said dry etching involves using a chlorine-based chemistry.25. The device of claim 21 , wherein said dry etching involves inductively-coupled plasma etching.26. The device of claim 21 , further comprising claim 21 , prior to step (a) claim 21 , n-doping said substrate above 1E17 cm-3.27. The device of claim 21 , wherein said substrate is part of a wafer and steps (a)-(d) are wafer level claim 21 , and further comprising (e) dicing said wafer to define said device.28. The device of claim 21 , wherein second contact is a p contact.29. The device of claim 28 , wherein the device is a light emitting diode (LED).30. The device of claim 21 , wherein the substrate has a resistivity less than about 0.050 Ω-cm.31. A semiconductor device having a height H and lateral dimension L claim 21 , and comprising:a bulk substrate comprising III-Nitride with an n-doping above 1E17 cm-3 and having an etched n-GaN surface;an n-contact disposed ...

Semiconductor light emitting device and method

A light-emitting device includes: a semiconductor structure formed on one side of a substrate, the semiconductor structure having a plurality of semiconductor layers and an active region within the layers; and first and second conductive electrodes contacting respectively different semiconductor layers of the structure; the substrate comprising a material having a refractive index n>2.0 and light absorption coefficient alpha, at the emission wavelength of the active region, of alpha>3 cm<-1>. In a preferred embodiment, the substrate material has a refractive index n>2.3, and the light absorption coefficient, alpha, of the substrate material is alpha<1 CM<-1>.

Selective filtering of wavelength-converted semiconductor light emitting devices

A structure includes a semiconductor light emitting device including a light emitting layer disposed between an n-type region and a p-type region. The light emitting layer emits first light of a first peak wavelength. A wavelength-converting material that absorbs the first light and emits second light of a second peak wavelength is disposed in the path of the first light. A filter material that transmits a portion of the first light and absorbs or reflects a portion of the first light is disposed over the wavelength-converting material.

Semiconductor light emitting devices grown on composite substrates

A plurality of III-nitride semiconductor structures, each including a light emitting layer disposed between an n-type region and a p-type region, are grown on a composite substrate. The composite substrate includes a plurality of islands of III-nitride material connected to a host by a bonding layer. The plurality of III-nitride semiconductor structures are grown on the III-nitride islands. The composite substrate may be formed such that each island of III-nitride material is at least partially relaxed. As a result, the light emitting layer of each semiconductor structure has an a-lattice constant greater than 3.19 angstroms.

Luminescent ceramic for a light emitting device

A semiconductor light emitting device comprising a light emitting layer disposed between an n-type region and a p-type region is combined with a ceramic layer which is disposed in a path of light emitted by the light emitting layer. The ceramic layer is composed of or includes a wavelength converting material such as a phosphor. Luminescent ceramic layers according to embodiments of the invention may be more robust and less sensitive to temperature than prior art phosphor layers. In addition, luminescent ceramics may exhibit less scattering and may therefore increase the conversion efficiency over prior art phosphor layers.

LUMINESCENT CERAMIC FOR A LIGHT EMITTING DEVICE

A semiconductor light emitting device comprising a light emitting layer disposed between an n-type region and a p-type region is combined with a ceramic layer which is disposed in a path of light emitted by the light emitting layer. The ceramic layer is composed of or includes a wavelength converting material such as a phosphor. Luminescent ceramic layers according to embodiments of the invention may be more robust and less sensitive to temperature than prior art phosphor layers. In addition, luminescent ceramics may exhibit less scattering and may therefore increase the conversion efficiency over prior art phosphor layers. 1. A method comprising:providing a light emitting device including a semiconductor structure comprising III-nitride light emitting layer disposed between an n-type region and a p-type region;mounting the light emitting device on a mount; andconnecting a ceramic layer comprising a wavelength converting material to a surface of the device from which light is extracted.2. The method of wherein providing a light emitting device comprises providing a semiconductor structure grown on a growth substrate claim 1 , the method further comprising removing the growth substrate from the semiconductor structure after mounting the light emitting device on a mount.3. The method of wherein mounting comprises mounting the light emitting device in a flip chip configuration.4. The method of wherein the mount has a lateral extent greater than the light emitting device.5. The method of wherein connecting comprises connecting the ceramic layer to a surface of a growth substrate.6. The method of wherein connecting comprises connecting the ceramic layer to a surface of a III-nitride layer. The method of wherein connecting comprises wafer bonding.8. The method of wherein connecting comprises sintering.9. The method of wherein connecting gluing with silicone.10. The method of wherein connecting comprises diffusion bonding in a uniaxial hot pressing apparatus.11. The method ...

CIRCADIAN-FRIENDLY LED LIGHT SOURCES

Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80.

CIRCADIAN FRIENDLY LED LIGHT SOURCE

Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80.

Package-integrated thin film LED

LED epitaxial layers (n-type, p-type, and active layers) are grown on a substrate. For each die, the n and p layers are electrically bonded to a package substrate that extends beyond the boundaries of the LED die such that the LED layers are between the package substrate and the growth substrate. The package substrate provides electrical contacts and conductors leading to solderable package connections. The growth substrate is then removed. Because the delicate LED layers were bonded to the package substrate while attached to the growth substrate, no intermediate support substrate for the LED layers is needed. The relatively thick LED epitaxial layer that was adjacent the removed growth substrate is then thinned and its top surface processed to incorporate light extraction features. There is very little absorption of light by the thinned epitaxial layer, there is high thermal conductivity to the package because the LED layers are directly bonded to the package substrate without any support ...

Power light emitting diode and method with current density operation

A light emitting diode device emitting at a wavelength of 390-415 nm has a bulk gallium and nitrogen containing substrate with an active region. The device has a current density of greater than about 175 Amps/cm 2 and an external quantum efficiency with a roll off of less than about 5% absolute efficiency.

Common optical element for an array of phosphor converted light emitting devices

A device is provided with an array of a plurality of phosphor converted light emitting devices (LEDs) that produce broad spectrum light. The phosphor converted LEDs may produce light with different correlated color temperature (CCT) and are covered with an optical element that assists in mixing the light from the LEDs to produce a desired correlated color temperature. The optical element may be bonded to the phosphor converted light emitting devices. The optical element may be a dome mounted over the phosphor converted light emitting devices and filled with an encapsulant.

Common optical element for an array of phosphor converted light emitting devices

A device is provided with at least one light emitting device (LED) die mounted on a submount with an optical element subsequently thermally bonded to the LED die. The LED die is electrically coupled to the submount through contact bumps that have a higher temperature melting point than is used to thermally bond the optical element to the LED die. In one implementation, a single optical element is bonded to a plurality of LED dice that are mounted to the submount and the submount and the optical element have approximately the same coefficients of thermal expansion. Alternatively, a number of optical elements may be used. The optical element or LED die may be covered with a coating of wavelength converting material. In one implementation, the device is tested to determine the wavelengths produced and additional layers of the wavelength converting material are added until the desired wavelengths are produced.

Circadian-friendly LED light sources

Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80.

Semiconductor Light Emitting Device Including Oxide Layer

A device includes a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region. The semiconductor structure is grown over an oxide layer disposed between first and second III-nitride layers. The oxide layer may at least partially relieve the strain in the light emitting layer by increasing the in-plane lattice constant of the template on which the light emitting layer is grown. The oxide layer may be formed by growing an AlInN layer in the device, etching a trench to expose the AlInN layer, then oxidizing the AlInN layer.

LED lamps with improved quality of light

LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm.

Thickness tailoring of wafer bonded AlxGayInzN structures by laser melting

Light emitting devices having a vertical optical path, e.g. a vertical cavity surface emitting laser or a resonant cavity light emitting or detecting device, having high quality mirrors may be achieved using wafer bonding or metallic soldering techniques. The light emitting region interposes one or two reflector stacks containing dielectric distributed Bragg reflectors (DBRs). The dielectric DBRs may be deposited or attached to the light emitting device. A host substrate of GaP, GaAs, InP, or Si is attached to one of the dielectric DBRs. Electrical contacts are added to the light emitting device.

Nucleation layer for improved light extraction from light emitting devices

A light emitting device including a nucleation layer containing aluminum is disclosed. The thickness and aluminum composition of the nucleation layer are selected to match the index of refraction of the substrate and device layers, such that 90% of light from the device layers incident on the nucleation layer is extracted into the substrate. In some embodiments, the nucleation layer is AlGaN with a thickness between about 1000 and about 1200 angstroms and an aluminum composition between about 2% and about 8%. In some embodiments, the nucleation layer is formed over a surface of a wurtzite substrate that is miscut from the c-plane of the substrate. In some embodiments, the nucleation layer is formed at high temperature, for example between 900° and 1200° C. In some embodiments, the nucleation layer is doped with Si to a concentration between about 3e18 cm<-3 >and about 5e19 cm<-3>.

Series connected flip chip LEDs with growth substrate removed

LED layers are grown over a sapphire substrate. Individual flip chip LEDs are formed by trenching or masked ion implantation. Modules containing a plurality of LEDs are diced and mounted on a submount wafer. A submount metal pattern or a metal pattern formed on the LEDs connects the LEDs in a module in series. The growth substrate is then removed, such as by laser lift-off. A semi-insulating layer is formed, prior to or after mounting, that mechanically connects the LEDs together. The semi-insulating layer may be formed by ion implantation of a layer between the substrate and the LED layers. PEC etching of the semi-insulating layer, exposed after substrate removal, may be performed by biasing the semi-insulating layer. The submount is then diced to create LED modules containing series-connected LEDs.

Method of forming light emitting devices with improved light extraction efficiency

A method of bonding a transparent optical element to a light emitting device having a stack of layers including semiconductor layers comprising an active region is provided. The method includes elevating a temperature of the optical element and the stack and applying a pressure to press the optical element and the stack together. In one embodiment, the method also includes disposing a layer of a transparent bonding material between the stack and the optical element. The bonding method can be applied to a premade optical element or to a block of optical element material which is later formed or shaped into an optical element such as a lens or an optical concentrator.

Bonding an optical element to a light emitting device

A device is provided with at least one light emitting device (LED) die mounted on a submount with an optical element subsequently thermally bonded to the LED die. The LED die is electrically coupled to the submount through contact bumps that have a higher temperature melting point than is used to thermally bond the optical element to the LED die. In one implementation, a single optical element is bonded to a plurality of LED dice that are mounted to the submount and the submount and the optical element have approximately the same coefficients of thermal expansion. Alternatively, a number of optical elements may be used. The optical element or LED die may be covered with a coating of wavelength converting material. In one implementation, the device is tested to determine the wavelengths produced and additional layers of the wavelength converting material are added until the desired wavelengths are produced.

Polarized Semiconductor Light Emitting Device

A light emitting device includes a light emitting diode (LED), a concentrator element, such as a compound parabolic concentrator, and a wavelength converting material, such as a phosphor. The concentrator element receives light from the LED and emits the light from an exit surface, which is smaller than the entrance surface. The wavelength converting material is, e.g., disposed over the exit surface. The radiance of the light emitting diode is preserved or increased despite the isotropic re-emitted light by the wavelength converting material. In one embodiment, the polarized light from a polarized LED is provided to a polarized optical system, such as a microdisplay. In another embodiment, the orthogonally polarized light from two polarized LEDs is combined, e.g., via a polarizing beamsplitter, and is provided to non-polarized optical system, such as a microdisplay. If desired, a concentrator element may be disposed between the beamsplitter and the microdisplay.

Circadian-friendly LED light source

Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80.

LED lamps with improved quality of light

LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm.

Circadian-friendly LED light source

Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80.

Photonic crystal light emitting device

A photonic crystal structure is formed in an n-type layer of a III-nitride light emitting device. In some embodiments, the photonic crystal n-type layer is formed on a tunnel junction. The device includes a first layer of first conductivity type, a first layer of second conductivity type, and an active region separating the first layer of first conductivity type from the first layer of second conductivity type. The tunnel junction includes a second layer of first conductivity type and a second layer of second conductivity type and separates the first layer of first conductivity type from a third layer of first conductivity type. A photonic crystal structure is formed in the third layer of first conductivity type.

Low Profile Side Emitting LED

Low profile, side-emitting LEDs are described, where all light is efficiently emitted within a relatively narrow angle generally parallel to the surface of the light-generating active layer. The LEDs enable the creation of very thin backlights for backlighting an LCD. In one embodiment, the LED is a flip chip with the n and p electrodes on the same side of the LED, and the LED is mounted electrode-side down on a submount. A reflector is provided on the top surface of the LED so that light impinging on the reflector is reflected back toward the active layer and eventually exits through a side surface of the LED. A waveguide layer and/or one or more phosphors layers are deposed between the semiconductor layers and the reflector for increasing the side emission area for increased efficiency. Side-emitting LEDs with a thickness of between 0.2-0.4 mm can be created.

Contact for a semiconductor light emitting device

An AlGaInP light emitting device is formed as a thin, flip chip device. The device includes a semiconductor structure comprising an AlGaInP light emitting layer disposed between an n-type region and a p-type region. N- and p-contacts electrically connected to the n- and p-type regions are both formed on the same side of the semiconductor structure. The semiconductor structure is connected to a mount via the contacts. A growth substrate is removed from the semiconductor structure and a thick transparent substrate is omitted, such that the total thickness of semiconductor layers in the device is less than 15 m some embodiments, less than 10 m in some embodiments. The top side of the semiconductor structure may be textured.

Bonding an optical element to a light emitting device

A device is provided with at least one light emitting device (LED) die mounted on a submount with an optical element subsequently thermally bonded to the LED die. The LED die is electrically coupled to the submount through contact bumps that have a higher temperature melting point than is used to thermally bond the optical element to the LED die. In one implementation, a single optical element is bonded to a plurality of LED dice that are mounted to the submount and the submount and the optical element have approximately the same coefficients of thermal expansion. Alternatively, a number of optical elements may be used. The optical element or LED die may be covered with a coating of wavelength converting material. In one implementation, the device is tested to determine the wavelengths produced and additional layers of the wavelength converting material are added until the desired wavelengths are produced.

LED with Porous Diffusing Reflector

In one embodiment, an AlInGaP LED includes a bottom n-type layer, an active layer, a top p-type layer, and a thick n-type GaP layer over the top p-type layer. The thick n-type GaP layer is then subjected to an electrochemical etch process that causes the n-type GaP layer to become porous and light-diffusing. Electrical contact is made to the p-GaP layer under the porous n-GaP layer by providing metal-filled vias through the porous layer, or electrical contact is made through non-porous regions of the GaP layer between porous regions. The LED chip may be mounted on a submount with the porous n-GaP layer facing the submount surface. The pores and metal layer reflect and diffuse the light, which greatly increases the light output of the LED. Other embodiments of the LED structure are described.

System and Method for Selected Pump LEDs with Multiple Phosphors

An LED pump light with multiple phosphors is described. LEDs emitting radiation at violet and/or ultraviolet wavelengths are used to pump phosphor materials that emit other colors. The LEDs operating in different wavelength ranges are arranged to reduce light re-absorption and improve light output efficiency.

SEMICONDUCTOR LIGHT EMITTING DEVICE GROWING ACTIVE LAYER ON TEXTURED SURFACE

In accordance with embodiments of the invention, at least partial strain relief in a light emitting layer of a III-nitride light emitting device is provided by configuring the surface on which at least one layer of the device grows such that the layer expands laterally and thus at least partially relaxes. This layer is referred to as the strain-relieved layer. In some embodiments, the light emitting layer itself is the strain-relieved layer, meaning that the light emitting layer is grown on a surface that allows the light emitting layer to expand laterally to relieve strain. In some embodiments, a layer grown before the light emitting layer is the strain-relieved layer. In a first group of embodiments, the strain-relieved layer is grown on a textured surface. 1. A method comprising:growing an n-type III-nitride region over a growth substrate;texturing a top surface of the III-nitride n-type region to form peaks alternating with valleys;growing islands of material on the peaks;laterally expanding the islands to form a layer that is at least partially relaxed; andgrowing a III-nitride light emitting layer over the textured top surface of the n-type region.2. The method of wherein growing a III-nitride light emitting layer comprises growing the III-nitride light emitting layer within 1000 angstroms of the textured top surface of the III-nitride n-type region.3. The method of wherein the distance between adjacent peaks is between 50 nm and 200 nm.4. The method of wherein growing a III-nitride light emitting layer comprises growing the III-nitride light emitting layer in direct contact with the textured top surface of the III-nitride n-type region.5. The method of wherein texturing a top surface of the III-nitride n-type region comprises forming peaks alternating with valleys by one of etching claim 1 , sputter etching claim 1 , and photoelectrochemical etching.6. The method of wherein texturing a top surface of the III-nitride n-type region comprises growing the III- ...

METHODS FOR RELAXATION AND TRANSFER OF STRAINED LAYERS AND STRUCTURES FABRICATED THEREBY

The present invention provides methods for forming at least partially relaxed strained material layers on a target substrate. The methods include forming islands of the strained material layer on an intermediate substrate, at least partially relaxing the strained material islands by a first heat treatment, and transferring the at least partially relaxed strained material islands to the target substrate. The at least partial relaxation is facilitated by the presence of low-viscosity or compliant layers adjacent to the strained material layer. The invention also provides semiconductor structures having an at least partially relaxed strained material layer, and semiconductor devices fabricated using an at least partially relaxed strained material layer.

LED lamps with improved quality of light

LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm.

POWER LIGHT EMITTING DIODE AND METHOD WITH CURRENT DENSITY OPERATION

A light emitting diode device emitting at a wavelength of 390-415 nm has a bulk gallium and nitrogen containing substrate with an active region. The device has a current density of greater than about 175 Amps/cmand an external quantum efficiency with a roll off of less than about 5% absolute efficiency. 1. A method of using a light emitting diode , the method comprising:providing a fixture comprising the light emitting diode, the light emitting diode comprising:a bulk gallium and nitrogen containing substrate having a surface region; andat least one active region formed overlying the surface region;{'sup': 2', '2, 'a current density from 175 Amps/cmto 2,000 Amps/cmcharacterizing the at least one active region; and'}wherein the light emitting diode is characterized by an external quantum efficiency (EQE) of at least 50%, and a peak emission wavelength between about 385 nm and about 480 nm; andemitting electromagnetic radiation having the peak emission wavelength between about 385 nm and 480 nm.2. The method of claim 1 , wherein the bulk gallium and nitrogen containing substrate is characterized by a growth on a non-polar orientation.3. The method of claim 1 , wherein the bulk gallium and nitrogen containing substrate is characterized by a growth orientation in on at least one of a plurality of semi-polar crystal planes selected from the (10-1-1) claim 1 , (11-22) claim 1 , (20-21) claim 1 , (20-2-1) claim 1 , (30-31) claim 1 , (30-3-1) claim 1 , (30-32) claim 1 , and (30-3-2) crystal plane claim 1 , and an offcut of any one of these planes within +/−5 degrees toward the c-direction and/or the α-direction.4. The method of claim 1 , further comprising at least one phosphor operably coupled to the at least one active region to produce a white light emission.5. The method of claim 1 , further comprising a junction area from about 0.0002 mmto about 1 mm.6. The method of claim 1 , wherein the bulk gallium and nitrogen containing substrate comprises at least one region ...

Low profile side emitting LED with window layer and phosphor layer

Low profile, side-emitting LEDs are described that generate white light, where all light is emitted within a relatively narrow angle generally parallel to the surface of the light-generating active layer. The LEDs enable the creation of very thin backlights for backlighting an LCD. In one embodiment, the LED emits blue light and is a flip chip with the n and p electrodes on the same side of the LED. Separately from the LED, a transparent wafer has deposited on it a red and green phosphor layer. The phosphor color temperature emission is tested, and the color temperatures vs. positions along the wafer are mapped. A reflector is formed over the transparent wafer. The transparent wafer is singulated, and the phosphor/window dice are matched with the blue LEDs to achieve a target white light color temperature. The phosphor/window is then affixed to the LED.

Substrate for growing a III-V light emitting device

A substrate including a host and a seed layer bonded to the host is provided, then a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region is grown on the seed layer. In some embodiments, a bonding layer bonds the host to the seed layer. The seed layer may be thinner than a critical thickness for relaxation of strain in the semiconductor structure, such that strain in the semiconductor structure is relieved by dislocations formed in the seed layer, or by gliding between the seed layer and the bonding layer an interface between the two layers. In some embodiments, the host may be separated from the semiconductor structure and seed layer by etching away the bonding layer.

Phosphor-converted light emitting device

A light source is disclosed that includes a light emitting device such as a III-nitride light emitting diode covered with a luminescent material structure, such as a single layer or multiple layers of phosphor. Any variations in the thickness of the luminescent material structure are less than or equal to 10% of the average thickness of the luminescent material structure. In some embodiments, the thickness of the luminescent material structure is less than 10% of a cross-sectional dimension of the light emitting device. In some embodiments, the luminescent material structure is the only luminescent material through which light emitted from the light emitting device passes. In some embodiments, the luminescent material structure is between about 15 and about 100 microns thick. The luminescent material structure is selectively deposited on the light emitting device by, for example, stenciling or electrophoretic deposition.

Semiconductor light emitting devices with graded composition light emitting layers

A III-nitride light emitting layer in a semiconductor light emitting device has a graded composition. The composition of the light emitting layer may be graded such that the change in the composition of a first element is at least 0.2% per angstrom of light emitting layer. Grading in the light emitting layer may reduce problems associated with polarization fields in the light emitting layer. The light emitting layer may be, for example In_xGa_1-xN, Al_xGa_1-xN, or In_xAl_yGa_1-x-yN.

Multi-Grain Luminescent Ceramics for Light Emitting Devices

A ceramic body is disposed in a path of light emitted by a light source. The light source may include a semiconductor structure comprising a light emitting region disposed between an n-type region and a p-type region. The ceramic body includes a plurality of first grains configured to absorb light emitted by the light source and emit light of a different wavelength, and a plurality of second grains. For example, the first grains may be grains of luminescent material and the second grains may be grains of a luminescent material host matrix without activating dopant.

Mount for a semiconductor light emitting device

A mount for a semiconductor device includes a carrier, at least two metal leads disposed on a bottom surface of the carrier, and a cavity extending through a thickness of the carrier to expose a portion of the top surfaces of the metal leads. A semiconductor light emitting device is positioned in the cavity and is electrically and physically connected to the metal leads. The carrier may be, for example, silicon, and the leads may be multilayer structures, for example a thin gold layer connected to a thick copper layer.

Polarization-reversed III-nitride light emitting device

A device structure includes a III-nitride wurtzite semiconductor light emitting region disposed between a p-type region and an n-type region. A bonded interface is disposed between two surfaces, one of the surfaces being a surface of the device structure. The bonded interface facilitates an orientation of the wurtzite c-axis in the light emitting region that confines carriers in the light emitting region, potentially increasing efficiency at high current density.

Substrate for growing a III-V light emitting device

A substrate including a host and a seed layer bonded to the host is provided, then a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region is grown on the seed layer. In some embodiments, a bonding layer bonds the host to the seed layer. The seed layer may be thinner than a critical thickness for relaxation of strain in the semiconductor structure, such that strain in the semiconductor structure is relieved by dislocations formed in the seed layer, or by gliding between the seed layer and the bonding layer an interface between the two layers. In some embodiments, the host may be separated from the semiconductor structure and seed layer by etching away the bonding layer.

LIGHT EMITTING DEVICES WITH IMPROVED LIGHT EXTRACTION EFFICIENCY

Light emitting devices with improved light extraction efficiency are provided. The light emitting devices have a stack of layers including semiconductor layers comprising an active region. The stack is bonded to a transparent lens having a refractive index for light emitted by the active region preferably greater than about 1.5, more preferably greater than about 1.8. A method of bonding a transparent lens to a light emitting device having a stack of layers including semiconductor layers comprising an active region includes elevating a temperature of the lens and the stack and applying a pressure to press the lens and the stack together. Bonding a high refractive index lens to a light emitting device improves the light extraction efficiency of the light emitting device by reducing loss due to total internal reflection. Advantageously, this improvement can be achieved without the use of an encapsulant. 119-. (canceled)20. A method comprising:mounting a light emitting device die to a submount through at least one contact element; andbonding an optical element to the light emitting device die after the light emitting device die is mounted to the submount, wherein the bonding of the optical element to the light emitting device die is effected by a bonding layer disposed between the optical element and the light emitting device die.21. The method of claim 24 , wherein the bonding layer comprises an inorganic material.22. The method of claim 24 , wherein bonding comprises elevating a temperature of the optical element claim 24 , the bonding layer claim 24 , the light emitting device die claim 24 , and the submount to a temperature that is less than the melting temperature of the contact element.23. The method of claim 24 , wherein the contact element is on at least one of the bottom surface of the light emitting device die and the top surface of the submount claim 24 , the contact element providing electrical contact between the light emitting device die and the submount. ...

Method for Growth of Indium-Containing Nitride Films

A method for growth of indium-containing nitride films is described, particularly a method for fabricating a gallium, indium, and nitrogen containing material. On a substrate having a surface region a material having a first indium-rich concentration is formed, followed by a second thickness of material having a first indium-poor concentration. Then a third thickness of material having a second indium-rich concentration is added to form a sandwiched structure which is thermally processed to cause formation of well-crystallized, relaxed material within a vicinity of a surface region of the sandwich structure.

RELAXATION OF STRAINED LAYERS

A method for relaxing a layer of a strained material. The method includes depositing a first low-viscosity layer on a first face of a strained material layer; bonding a first substrate to the first low-viscosity layer to form a first composite structure; subjecting the composite structure to heat treatment sufficient to cause reflow of the first low-viscosity layer so as to at least partly relax the strained material layer; and applying a mechanical pressure to a second face of the strained material layer wherein the second face is opposite to the first face and with the mechanical pressure applied perpendicularly to the strained material layer during at least part of the heat treatment to relax the strained material. 1. A method for relaxing a layer of a strained material which comprises:depositing a first low-viscosity layer on a first face of a strained material layer;bonding a first substrate to the first low-viscosity layer to form a first composite structure;subjecting the composite structure to heat treatment sufficient to cause reflow of the first low-viscosity layer so as to at least partly relax the strained material layer; andapplying a mechanical pressure to a second face of the strained material layer wherein the second face is opposite to the first face and with the mechanical pressure applied perpendicularly to the strained material layer during at least part of the heat treatment.2. The method according to claim 1 , which further comprises depositing a second low-viscosity layer on a second face of the strained-material layer to form a sandwich structure prior to applying the mechanical pressure so that the second low-viscosity layer helps to at least partly relax the strained material layer.3. The method according to claim 2 , wherein the composite structure is subjected to the heat treatment to cause reflow of both the first and second low-viscosity layers so as to at least partly relax the strained-material layer within the first sandwich ...

III-V LIGHT EMITTING DEVICE INCLUDING A LIGHT EXTRACTING STRUCTURE

Embodiments of the invention include a substrate comprising a host and a seed layer bonded to the host, and a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region grown over the seed layer. A variation in index of refraction in a direction perpendicular to a growth direction of the semiconductor structure is disposed between the host and the light emitting layer. 115-. (canceled)16. A structure comprising: a host; and', 'a seed layer bonded to the host;, 'a substrate comprisinga semiconductor structure grown over the seed layer, the semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region; anda variation in index of refraction disposed between the host and the light emitting layer, the variation in index of refraction comprising hills of first material having a first index of refraction separated by valleys of a second material having a second index of refraction.17. The structure of wherein the hills comprise pillars.18. The structure of wherein the hills comprise pyramids.19. The structure of wherein:{'sub': 2', '2', '5, 'one of the first and second materials is one of III-nitride material, high index glass, TiO, and TaO; and'}{'sub': 2', '2', '2, 'the other of the first and second materials is one of SiO, MgF, CaF, air, porous material, porous oxide, and porous dielectric.'}20. The structure of wherein a difference between the first index of refraction and the second index of refraction is at least 0.1.21. The structure of wherein a difference between the first index of refraction and the second index of refraction is at least 0.5.22. The structure of wherein the hills are between 100 nm and 10 microns high.23. A structure comprising: a non-III-nitride host; and', 'a III-nitride seed layer bonded to the host by a bonding layer;, 'a substrate comprisinga semiconductor structure grown over the seed layer, the semiconductor structure comprising a light ...

Bonding an optical element to a light emitting device

A device is provided with at least one light emitting device (LED) die mounted on a submount with an optical element subsequently thermally bonded to the LED die. The LED die is electrically coupled to the submount through contact bumps that have a higher temperature melting point than is used to thermally bond the optical element to the LED die. In one implementation, a single optical element is bonded to a plurality of LED dice that are mounted to the submount and the submount and the optical element have approximately the same coefficients of thermal expansion. Alternatively, a number of optical elements may be used. The optical element or LED die may be covered with a coating of wavelength converting material. In one implementation, the device is tested to determine the wavelengths produced and additional layers of the wavelength converting material are added until the desired wavelengths are produced.

PACKAGE-INTEGRATED THIN FILM LED

LED epitaxial layers (n-type, p-type, and active layers) are grown on a substrate. For each die, the n and p layers are electrically bonded to a package substrate that extends beyond the boundaries of the LED die such that the LED layers are between the package substrate and the growth substrate. The package substrate provides electrical contacts and conductors leading to solderable package connections. The growth substrate is then removed. Because the delicate LED layers were bonded to the package substrate while attached to the growth substrate, no intermediate support substrate for the LED layers is needed. The relatively thick LED epitaxial layer that was adjacent the removed growth substrate is then thinned and its top surface processed to incorporate light extraction features. There is very little absorption of light by the thinned epitaxial layer, there is high thermal conductivity to the package because the LED layers are directly bonded to the package substrate without any support substrate therebetween, and there is little electrical resistance between the package and the LED layers so efficiency (light output vs. power input) is high. The light extraction features of the LED layer further improves efficiency. 1. A method comprising:providing a wafer comprising light emitting diode (LED) layers grown on a growth substrate, the LED layers comprising a first epitaxial layer of a first conductivity type, a second epitaxial layer of a second conductivity type, and an active layer disposed between the first and second epitaxial layers;dicing the wafer;after dicing the wafer, removing the growth substrate; andafter removing the growth substrate, roughening the LED layers.2. The method of wherein roughening the LED layers comprises roughening a top surface of the LED layers.3. The method of wherein roughening the LED layers comprises photo-electrochemically etching the LED layers.4. The method of wherein dicing the wafer comprises dicing the wafer into separate ...

INDIUM GALLIUM NITRIDE LIGHT EMITTING DEVICES

InGaN-based light-emitting devices fabricated on an InGaN template layer are disclosed. 1. A light emitting device comprising:a gallium- and indium-containing nitride substrate;an n-type layer overlying the substrate;an active layer overlying the n-type layer; anda p-type layer overlying the active layer;wherein the gallium- and indium-containing nitride substrate comprises a thickness greater than 4 μm and an InN composition greater than 0.5%.2. The light emitting device of claim 1 , wherein the substrate is characterized by a wurtzite crystal structure and a crystallographic orientation of a large area surface within about 5 degrees of one of the (0001) +c-plane and the (000-1) —c-plane.3. The light emitting device of claim 1 , wherein the substrate is substantially crack-free.4. The light emitting device of claim 1 , wherein the gallium- and indium-containing nitride substrate is relaxed claim 1 , having a-axis and c-axis lattice constants within 0.1% of the equilibrium lattice constants for a specific indium-containing nitride composition.5. The light emitting device of claim 1 , wherein the gallium- and indium-containing nitride substrate is relaxed claim 1 , having a-axis and c-axis lattice constants within 0.01% of the equilibrium lattice constants for a specific indium-containing nitride composition.6. The light emitting device of claim 1 , wherein the gallium- and indium-containing nitride substrate is relaxed claim 1 , having a-axis and c-axis lattice constants within 0.001% of the equilibrium lattice constants for a specific indium-containing nitride composition.7. The light emitting device of claim 1 , further comprising at least one of claim 1 , a lamp claim 1 , a luminaire claim 1 , and a lighting system claim 1 , wherein the light emitting device is incorporated into the lamp claim 1 , the luminaire claim 1 , or the lighting system.8. A light emitting device comprising:a substrate;an n-type layer overlying the substrate;an active layer overlying the n ...

LED LAMPS WITH IMPROVED QUALITY OF LIGHT

LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm. 130-. (canceled)31. An illumination system comprising:at least one LED device configured in a housing structure, wherein the at least one LED device comprises an n-type region, a light-emitting active region, and a p-type region;a wavelength conversion material optically coupled to the at least one LED device; anda power source electrically coupled to the at least one LED device; wherein,{'sup': '2', 'the at least one LED device is characterized by an external quantum efficiency greater than 45% measured at an ambient temperature of 25° C. and at a current density of 40 A/cm;'}light is emitted by an interaction of electromagnetic radiation emitted from the at least one LED device and the wavelength conversion material; andlight emitted by the illumination system is characterized by a spectral power distribution (SPD) in which the fraction of the SPD in the range from about 390 nm to about 430 nm is between 2% and 25%.32. The illumination system of claim 31 , wherein the at least one LED device comprises a gallium and nitride-containing substrate.33. The illumination system of claim 31 , wherein the at least one LED is configured to emit electromagnetic radiation within a short-wavelength range from about 390 nm to about 430 nm.34. The illumination system of claim 31 , wherein claim 31 ,the wavelength conversion material comprises a blue phosphor and a green phosphor; andthe green phosphor is configured to absorb electromagnetic radiation emitted by the blue phosphor.35. The illumination system of claim 31 , comprising a second LED device claim 31 , wherein the second LED device is configured to emit electromagnetic radiation within a blue wavelength range claim 31 , within a green wavelength range claim 31 , or within a red wavelength ...

POWER LIGHT EMITTING DIODE AND METHOD WITH UNIFORM CURRENT DENSITY OPERATION

A light emitting diode device has a bulk gallium and nitrogen containing substrate with an active region. The device has a lateral dimension and a thick vertical dimension such that the geometric aspect ratio forms a volumetric diode that delivers a nearly uniform current density across the range of the lateral dimension. 120-. (canceled)21. An LED optical device comprising:a bulk GaN substrate;an active region over said substrate, said active region having an active region area;a light-emitting outer surface over said active region, said light-emitting outer surface having a light-emitting outer surface area; andwherein the ratio of said light-emitting outer surface area to active region area is greater than 5.22. The LED of claim 21 , wherein said ratio is greater than 10.23. The LED of claim 21 , wherein said ratio is greater than 100.24. The LED of claim 21 , wherein said LED is configured to emit at least 300 lumens of white light from said light-emitting outer surface.25. The LED of claim 21 , wherein said LED is configured to operate at a power density great than 2 W/mm2 of active region.26. The LED of claim 21 , wherein said active region emits light having a wavelength of 385 nm to 415 nm or 415 nm to 440 nm.27. An array comprising a plurality of LEDs of .28. The LED of claim 27 , wherein said active region of each of said plurality of LED emits light having a wavelength of 385 nm to 415 nm or 415 nm to 440 nm.29. The LED of claim 27 , wherein said active region of at least one of said plurality of LEDs emits light having a wavelength of 380 nm to 440 nm and said active region of another of said plurality of LEDs emits light having a wavelength of 385 nm to 480 nm.30. The LED of claim 29 , wherein said active region of said another of said plurality of LEDs emits light having a wavelength of 440 nm to 470 nm. This application is a continuation of U.S. application Ser. No. 15/700,562 filed on Sep. 11, 2017, now U.S. Pat. No. 9,985,179, which is a ...

LED LAMPS WITH IMPROVED QUALITY OF LIGHT

LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm. 1at least one LED device configured in a housing structure, wherein said at least one LED device comprises an n-type region, a light-emitting active region, and a p-type region, said at least one LED device configured to emit LED light having a peak emission wavelength of about 405nm, said at least one LED device having an external quantum efficiency greater than 45% measured at an ambient temperature of 25° C. and at a current density of 40 A/cm2;a wavelength conversion material optically coupled to said at least one LED device and configured to emit converted light;a power source electrically coupled to said at least one LED device; andwherein said illumination system emits emitted light comprising a combination of said LED light and said converted light, said emitted light has a spectral power distribution (SPD) having a correlated color temperature (CCT) and an International Commission on Illumination (CIE) whiteness, said CIE whiteness being at least equal to a reference CIE whiteness of a blackbody radiator with the same CCT, and wherein said SPD has a first power from 380 nm to 800 nm and a second power from 390 nm to about 430 nm, wherein said second power is at least 4% of said first power.. An illumination system comprising: This application is a continuation of U.S. application Ser. No. 16/786,277, filed Feb. 10, 2020, which is a continuation of U.S. application Ser. No. 16/203,045, filed Nov. 28, 2018, now U.S. Pat. No. 10,557,595, issued Feb. 11, 2020, which is a continuation of U.S. application Ser. No. 16/031,144, filed Jul. 10, 2018, now U.S. Pat. No. 10,168,009, issued Jan. 1, 2019, which is a continuation of U.S. application Ser. No. 15/618,236, filed Jun. 9, 2017, now U.S. Pat. No. 10,139,056, issued Nov. 27, 2018, which ...

III-NITRIDE LIGHT EMITTING DEVICE WITH DOUBLE HETEROSTRUCTURE LIGHT EMITTING REGION

A III-nitride light emitting layer is disposed between an n-type region and a p-type region in a double heterostructure. At least a portion of the III-nitride light emitting layer has a graded composition. 1. (canceled)2. A semiconductor light emitting device comprising:an n-type region;a p-type region; and the light emitting layer has a thickness between 100 Å and 600 Å,', 'the light emitting layer is devoid of any barrier layer,', 'a least a portion of the light emitting layer has a graded InN compostion; and', 'a plot of InN composition as a function of distance from the n-type region for the light emitting layer comprises a plurality of local minima in InN composition., 'a light emitting region disposed between the n-type region and the p-type region in a double-heterostructure that includes only a single III-nitride light emitting layer, this light emitting layer being the only layer in the device from which light is produced when current flows betwee the n-type and p-type region, wherein'}3. The semiconductor light emitting device of wherein the plot of InN composition as a function of distance from the n-type region for the light emitting layer includes a local maximum in InN composition in a portion of the light emitting layer closest to the n-type region.4. The semiconductor light emitting device of wherein the plot of InN composition as a function of distance from the n-type region for the light emitting layer includes a local maximum in InN composition disposed between two local minima in InN composition.5. The semiconductor light emitting device of wherein the InN composition between the local maximum and one of the two local minima is linearly graded.6. The semiconductor light emitting device of wherein each local minima in the plot of InN composition corresponds to a portion of the light emitting layer with a constant InN composition.7. The semiconductor light emitting device of wherein regions between local maxima in the plot of InN composition do not ...

LIGHT EMITTING DEVICES WITH IMPROVED LIGHT EXTRACTION EFFICIENCY

Light emitting devices with improved light extraction efficiency are provided. The light emitting devices have a stack of layers including semiconductor layers comprising an active region. The stack is bonded to a transparent optical element. 1. A light emitting device having a stack of layers including semiconductor layers comprising an active region , said device comprising:a transparent optical element bonded to a surface of the stack by a bonding layer, wherein the bonding layer is selected from the group consisting of glass having an optical index greater than 1.8, Schott glass SF59, Schott glass LaSF 3, and Schott glass LaSF N18.2. The light emitting device of wherein a smallest ratio of a length of a base of said optical element to a length of said surface is greater than one.3. The light emitting device of further comprising luminescent material included in the bonding layer.4. The light emitting device of wherein the luminescent material is one of quantum dots and nanocrystals.5. The light emitting device of further comprising luminescent material included in the optical element.6. A light emitting device having a stack of layers including semiconductor layers comprising an active region claim 1 , said device comprising:a transparent optical element bonded to a surface of the stack by a bonding layer, wherein the bonding layer is selected from the group consisting of metal oxide, tungsten oxide, titanium oxide, nickel oxide, zirconium oxide, indium tin oxide, and chromium oxide.7. The light emitting device of wherein a smallest ratio of a length of a base of said optical element to a length of said surface is greater than one.8. The light emitting device of further comprising luminescent material included in the bonding layer.9. The light emitting device of wherein the luminescent material is one of quantum dots and nanocrystals.10. The light emitting device of further comprising luminescent material included in the optical element.11. A light emitting ...

SYSTEM AND METHOD FOR PROVIDING COLOR LIGHT SOURCES IN PROXIMITY TO PREDETERMINED WAVELENGTH CONVERSION STRUCTURES

An optical device includes a light source with at least two radiation sources, and at least two layers of wavelength-modifying materials excited by the radiation sources that emit radiation in at least two predetermined wavelengths. Embodiments include a first plurality of n radiation sources configured to emit radiation at a first wavelength. The first plurality of radiation sources are in proximity to a second plurality of m of radiation sources configured to emit radiation at a second wavelength, the second wavelength being shorter than the first wavelength. The ratio between m and n is predetermined. The disclosed optical device also comprises at least two wavelength converting layers such that a first wavelength converting layer is configured to absorb a portion of radiation emitted by the second radiation sources, and a second wavelength converting layer configured to absorb a portion of radiation emitted by the second radiation sources. 130-. (canceled)31. An optical device comprising:a plurality of light emitting diode (LED) light sources comprising at least a first LED light source and a second LED light source, said first LED light source emitting radiation having a peak first wavelength in a range of about 420 nm to about 490 nm, said second LED light source emitting radiation having a peak second wavelength shorter than said first wavelength;at least one wavelength-converting material disposed in a radiation path of at least one of said plurality of LED light sources, and configured to convert radiation from said at least one of said plurality of LED light sources to radiation having a peak third wavelength in a range of about 500 nm to about 650 nm;wherein the optical device outputs a resulting radiation from said plurality of LED light sources and said at least one wavelength-converting material.32. The optical device of claim 31 , wherein said second peak wavelength is between 380 nm and 470 nm.33. The optical device of claim 31 , wherein said second ...

III-NITRIDE LIGHT EMITTING DEVICE WITH DOUBLE HETEROSTRUCTURE LIGHT EMITTING REGION

A III-nitride light emitting layer is disposed between an n-type region and a p-type region in a double heterostructure. At least a portion of the III-nitride light emitting layer has a graded composition. 1. (canceled)2. A semiconductor light emitting device comprising:an n-type region;a p-type region; and the light emitting layer has a thickness between 100 Å and 600 Å,', 'the light emitting layer is devoid of any barrier layer,', 'a least a portion of the light emitting layer has a graded InN compostion; and', 'a plot of InN composition as a function of distance from the n-type region for the light emitting layer comprises a plurality of local minima in InN composition., 'a light emitting region disposed between the n-type region and the p-type region in a double-heterostructure that includes only a single III-nitride light emitting layer, this light emitting layer being the only layer in the device from which light is produced when current flows betwee the n-type and p-type region, wherein'}3. The semiconductor light emitting device of wherein the plot of InN composition as a function of distance from the n-type region for the light emitting layer includes a local maximum in InN composition in a portion of the light emitting layer closest to the n-type region.4. The semiconductor light emitting device of wherein the plot of InN composition as a function of distance from the n-type region for the light emitting layer includes a local maximum in InN composition disposed between two local minima in InN composition.5. The semiconductor light emitting device of wherein the InN composition between the local maximum and one of the two local minima is linearly graded.6. The semiconductor light emitting device of wherein each local minima in the plot of InN composition corresponds to a portion of the light emitting layer with a constant InN composition.7. The semiconductor light emitting device of wherein regions between local maxima in the plot of InN composition do not ...

INDIUM-GALLIUM-NITRIDE STRUCTURES AND DEVICES

InGaN layers characterized by an in-plane lattice parameter within a range from 3.19 Å to 3.50 Å are disclosed. The InGaN layers are grown by coalescing InGaN grown on a plurality of GaN seed regions. The InGaN layers can be used to fabricate optical and electronic devices for use in light sources for illumination and display applications. 1. A III-nitride semiconductor structure , comprising:{'sub': x', '1-x, '(a) seed regions comprising InGaN (0≤x<1) and a Wurtzite III-nitride crystal structure;'} [{'sub': x', '1-x', 'y', '1-y, 'an intersection of the first plane and a first edge of a seed region locates a InGaN/InGaN heterojunction, wherein 0x; and'}, {'sub': x', '1-x', 'y', '1-y, 'the InGaN/InGaN heterojunction is coplanar with a first crystallographic plane of the seed region;'}], '(b) a first plane parallel to a (0001) plane of the Wurtzite III-nitride structure and intersecting the seed regions; wherein,'}(c) any second plane parallel to the (0001) plane of the Wurtzite III-nitride crystal structure and intersecting a second edge of the seed region locates a III-nitride heterojunction, wherein the III-nitride heterojunction is coplanar with a second crystallographic plane of the seed region; and(d) a (0001) InGaN region overlies the seed regions, wherein the (0001) InGaN region is characterized by an in-plane a-lattice parameter that is greater than 3.19 Å,wherein each of the first crystallographic plane and the second crystallographic plane is crystallographically equivalent.2. The semiconductor structure of claim 1 , wherein the first edge and the second edge are different edges.3. The semiconductor structure of claim 1 , wherein the first edge and the second edge are the same edge.4. The semiconductor structure of claim 1 , wherein the first crystallographic plane and the second crystallographic plane are different crystallographic planes.5. The semiconductor structure of claim 1 , wherein the first crystallographic plane and the second ...

Apportioning optical projection paths in an led lamp

A light-emitting system for emitting light, comprising: (a) at least one light-emitting diode (LED) configured to emit LED light; (b) at least one optical element optically coupled to said at least one LED and configured to direct a first fraction of said LED light along a first optical path and a second fraction of said LED light along a second optical path; and (c) a color modification element disposed along said second optical path and configured to modify the spectrum of said second fraction of said LED light to emit modified light.

CIRCADIAN-FRIENDLY LED LIGHT SOURCE

Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80. 1. (canceled)2. A light source comprising:at least one first solid-state light emitting device emitting a first light having a peak in a range 420 to 430 nm, and one or more radiation sources for emitting second light of one or more wavelengths;wherein said light source is configured in at least a first way to emit a first emitted light comprising at least a portion of said first light and said second light, the first emitted light being substantially white light characterized by a first spectral power distribution (SPD), a first CCT, and a first chromaticity; andwherein the power of said first SPD in the range of 400 to 440 nm is more than 8% of the power of said first SPD in the range of 380 to 850 nm, said CCT is in a range of about 2500° to about 5000° K, and said chromaticity is within +/− five Du'v' points of a Planckian locus when calculated with the 1964 CIE color matching functions.3. The light source of claim 2 , wherein said first emitted light has a color rendering index Ra above 80.4. The light source of claim 2 , wherein said first emitted light has a color rendering index R9 above 80.5. The light source of claim 2 , wherein said radiation sources are color-converting materials excited by said first light.6. The light source of claim 2 , further comprising at least one second solid-state light-emitting device emitting a third light having a peak in a range 440 to 500 nm.7. The light source of claim 6 , configured in a second way ...

POWER LIGHT EMITTING DIODE AND METHOD WITH UNIFORM CURRENT DENSITY OPERATION

A light emitting diode device has a bulk gallium and nitrogen containing substrate with an active region. The device has a lateral dimension and a thick vertical dimension such that the geometric aspect ratio forms a volumetric diode that delivers a nearly uniform current density across the range of the lateral dimension. 1. A light emitting diode (LED) having a bulk gallium- and nitrogen-containing substrate;an epitaxial stack comprising an n-type layer, an active region, and a p-type layer disposed on said substrate;an electrical n-contact contacting said n-type layer;an electrical p-contact contacting said p-type layer; andwherein at least one of said substrate, epitaxial stack, said n-contact, and said p-contact is configured to reduce current crowding such that light emitted from the active region has an emission intensity varying no more than +/−20% across the active region at an input power per active region area greater than 2 watts/mm2.2. The LED of claim 1 , wherein the substrate is a bulk GaN substrate.3. The LED of claim 1 , wherein the light emitting diode is configured to emit light from the active region having an emission intensity varying no more than +/−10% across the active region at an input power per active region area greater than 2 watts/mm2.4. The LED of claim 1 , wherein the light emitting diode is configured to emit light from the active region having an emission intensity varying no more than +/−20% across the active region at an input power per active region area greater than 5 watts/mm2.5. The LED of claim 4 , wherein the light emitting diode is configured to emit light from the active region having an emission intensity varying no more than +/−10% across the active region claim 4 , at an input power per active region area greater than 5 watts/mm2.6. The LED of claim 1 , wherein the LED is a flip-chip LED.7. The LED of claim 1 , wherein the LED emits light with a wavelength in a range of 390 nm to 480 nm.8. The LED of claim 1 , wherein ...

LED LAMPS WITH IMPROVED QUALITY OF LIGHT

LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm. 1. (canceled)2. An illumination system comprising:at least one LED device configured to emit LED light having a peak emission wavelength within a range 405-430 nm, said at least one LED device having an external quantum efficiency greater than 45% measured at an ambient temperature of 25° C. and at a current density of 40 A/cm2;a wavelength conversion material optically coupled to said at least one LED device and configured to emit converted light; andwherein said illumination system emits emitted light comprising a combination of said LED light and said converted light, said emitted light has a spectral power distribution (SPD) having a CCT and a CIE whiteness, and wherein said SPD has a first power from 380 nm to 800 nm and a second power from 390 nm to about 430 nm, wherein said second power is a sufficient portion of said first power such that said CIE whiteness is at least equal to a reference CIE whiteness of a blackbody radiator having the same CCT.3. The illumination system of claim 2 , wherein said second power is at least at least 4% of said first power.4. The illumination system of claim 2 , wherein said second power is less than 25% of said first power.5. The illumination system of claim 2 , wherein said emitted light has a chromaticity on or below the Planckian Locus.6. The illumination system of claim 2 , wherein said CCT is between 3300K and 5300K.7. The lighting system of claim 2 , wherein said emitted light has a color rendering index (CRI) greater than 80.8. The illumination system of claim 2 , wherein SPD has a cyanosis observation index (COI) below 3.3.9. A lighting fixture comprising the lighting system of .10. A method of using the lighting fixture of in a medical setting.11. An illumination system comprising:at least ...

CIRCADIAN-FRIENDLY LED LIGHT SOURCE

Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80. 1. (canceled)2. A light emitter comprising:one or more LEDs configured to emit LED light, said one or more LEDs comprising at least a violet LED configured to emit a light with a peak wavelength around 405 nm;at least one phosphor configured to emit converted light by converting a fraction of said LED light; andwherein said light emitter emits an emitted light comprising at least a combination of a fraction of said LED light and said converted light, said emitted light having a spectral power distribution (SPD), said SPD having a first power from 350 nm to 850 nm and a second power from 400 nm to about 440 nm, and a third power from about 440 to about 500 nm, wherein said second power is at least 10% of said first power, wherein the ratio said second power to said third power is at least 1 and no greater than 5, and wherein said SPD has a CRI greater than 80 and an R9 greater than 0.3. The light emitter of claim 2 , wherein at least a portion light emitted from said violet LED pumps said at least one phosphor.4. The light emitter of claim 2 , wherein one or more LEDs comprises a second LED configured to emit a second light claim 2 , wherein said one or more LEDs are configured to emit at least a first LED light and a second LED light by varying the amount of said at least one violet LED and said at least one second LED in said LED light.5. The light emitter of claim 4 , wherein said second LED comprises a blue LED.6. The light emitter of claim ...

LED LAMPS WITH IMPROVED QUALITY OF LIGHT

LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm. 1. A three-way lighting system comprising:a first light emitting diode (LED) configured to emit first light having a first spectral power distribution (SPD);a second LED configured to emit second light having a second SPD substantially different from said first SPD;a driver coupled to said first LED and said second LED and configured to selectively power said first LED to emit said first light and said second LED to emit said second light, wherein said driver is configured to interface with a user-operated switch to operate in at least first, second, and third modes, in said first mode, said driver is configured to power one of said first LED and said second LED, in said second mode, said driver is configured to power both of said first LED and said second LED, and in said third mode, said driver is configured to power neither of said first LED and said second LED.2. The lighting system of claim 1 , wherein in said first mode claim 1 , said driver is configured to power said first LED.3. The lighting system of claim 2 , further comprising a fourth mode claim 2 , wherein said driver is configured power said second LED and operate said first LED in an off state.4. The lighting system of claim 1 , wherein said first light has a first correlated color temperature (CCT) and said second light has a second CCT different from said first CCT.5. The lighting system of claim 1 , wherein said first light has a color rendering index (CRI) greater than 90.6. The lighting system of claim 1 , wherein said first SPD and said second SPD are substantially white.7. The lighting system of claim 6 , wherein about 4% to about 25% of power of said first SPD is emitted within a wavelength range from about 390 nm to about 430 nm.8. The lighting system of claim 1 , ...

LIGHT EMITTING DEVICES WITH OPTICAL ELEMENTS AND BONDING LAYERS

Light emitting devices with improved light extraction efficiency are provided. The light emitting devices have a stack of layers including semiconductor layers comprising an active region. The stack is bonded to a transparent optical element. 1. A device comprising:a light emitting diode (LED) die comprising semiconductor layers including an active region, the LED die having a first coefficient of thermal expansion;a transparent optical element bonded to a surface of the LED die, the transparent optical element having a second coefficient of thermal expansion approximately equal to the first coefficient of thermal expansion.2. The device of further comprising a bonding layer disposed between the LED die and the transparent optical element.3. The device of wherein:the LED die comprises a metal contact;an electrically conductive layer is disposed on a surface of the transparent optical element facing the LED die; andthe bonding layer is patterned to permit the metal contact to make electrical contact to the electrically conductive layer.4. The device of wherein the electrically conductive layer is indium tin oxide.5. The device of wherein the bonding layer is selected from the group consisting of ZnS and ZnSe and the semiconductor layers comprise GaN.6. The device of wherein the transparent optical element is selected from the group consisting of ZnS and ZnSe and the semiconductor layers comprise GaN.7. The device of wherein:{'sub': 'lens', 'the transparent optical element has a refractive index n;'}{'sub': 'bond', 'the bonding layer has a refractive index n;'}{'sub': 'LED', 'a top layer of the LED die has a refractive index n; and'}{'sub': LED', 'bond', 'lens, 'n≦n≦n.'}8. The device of wherein:{'sub': 'lens', 'the transparent optical element has a refractive index n;'}{'sub': 'bond', 'the bonding layer has a refractive index n;'}{'sub': 'LED', 'a top layer of the LED die has a refractive index n; and'}{'sub': LED', 'lens', 'bond, 'n≦n≦n.'}9. The device of wherein:{' ...

CIRCADIAN-FRIENDLY LED LIGHT SOURCE

Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80. 1. A light emitter comprising:one or more LEDs configured to emit LED light, said one or more LEDs comprising at least a violet pump LED configured to emit a pump light with a peak wavelength around 405 nm;at least one phosphor configured to emit converted light by converting a fraction of said pump light; andwherein said light emitter emits an emitted light formed by a combination of a fraction of said LED light and said converted light, said emitted light having a spectral power distribution (SPD), said SPD has a first power from 350 nm to 850 nm and a second power from 400 nm to about 440 nm, wherein said second power is at least 25% of said first power, and wherein said SPD has a CRI greater than 80 and an R9 greater than 0.2. The light emitter of claim 1 , wherein said one or more LEDs comprises at least one blue LED.3. The light emitter of claim 1 , further comprising a blue emitter.4. The light emitter of claim 3 , wherein said blue emitter is a blue LED.5. The light emitter of claim 3 , wherein said blue emitter is a phosphor.6. The light emitter of claim 1 , wherein said R9 is at least 50.7. The light emitter of claim 1 , wherein said emitted light has a chromaticity within +/−five Du′v′ points of the Planckian locus.8. The light emitter of claim 1 , wherein said emitted light has a chromaticity below the Planckian locus.9. The light emitter of claim 1 , wherein said SPD has a CCT ranging from about 3000K to about 9000K.10. The light ...

LED LAMPS WITH IMPROVED QUALITY OF LIGHT

LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm. 1. An illumination system comprising:at least one LED device configured in a housing structure, wherein the at least one LED device comprises an n-type region, a light-emitting active region, and a p-type region;a wavelength conversion material optically coupled to the at least one LED device; anda power source electrically coupled to the at least one LED device; wherein,{'sup': '2', 'the at least one LED device is characterized by an external quantum efficiency greater than 45% measured at an ambient temperature of 25° C. and at a current density of 40 A/cm; and'}light emitted by an interaction of electromagnetic radiation emitted from the at least one LED device and from the wavelength conversion material is characterized by a spectral power distribution (SPD) in which from 1% to 4% of the power in the SPD is emitted within a short-wavelength range from about 390 nm to about 430 nm.2. The illumination system of claim 1 , wherein the LED device comprises a gallium and nitride-containing substrate.3. The illumination system of claim 1 , wherein the at least one LED is configured to emit electromagnetic radiation within the short-wavelength range from about 390 nm to about 430 nm.4. The illumination system of claim 1 , wherein claim 1 ,the wavelength conversion material comprises a blue phosphor and a green phosphor; andthe green phosphor is configured to absorb electromagnetic radiation emitted by the blue phosphor.5. The illumination system of claim 1 , comprising a second LED device claim 1 , wherein the second LED device is configured to emit electromagnetic radiation within a blue wavelength range claim 1 , within a green wavelength range claim 1 , or within a red wavelength range.6. The illumination system of claim 1 , comprising one ...

LED LAMPS WITH IMPROVED QUALITY OF LIGHT

LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm. 1. An illumination system comprising:at least one LED device configured in a housing structure, wherein said at least one LED device comprises an n-type region, a light-emitting active region, and a p-type region, said at least one LED device configured to emit LED light having a peak emission wavelength of about 405 nm, said at least one LED device having an external quantum efficiency greater than 45% measured at an ambient temperature of 25° C. and at a current density of 40 A/cm2;a wavelength conversion material optically coupled to said at least one LED device and configured to emit converted light;a power source electrically coupled to said at least one LED device; andwherein said illumination system emits emitted light comprising a combination of said LED light and said converted light, said emitted light has a spectral power distribution (SPD) having a correlated color temperature (CCT) and an International Commission on Illumination (CIE) whiteness, said CIE whiteness being at least equal to a reference CIE whiteness of a blackbody radiator with the same CCT, and wherein said SPD has a first power from 380 nm to 800 nm and a second power from 390 nm to about 430 nm, wherein said second power is at least 4% of said first power.2. The illumination system of claim 1 , wherein said second power is less than 25% of said first power.3. The illumination system of claim 1 , wherein said emitted light has a chromaticity on or below the Planckian Locus.4. The illumination system of claim 1 , wherein said CCT is between 3300K and 5300K.5. The illumination system of claim 1 , wherein SPD has a cyanosis observation index (COI) below 3.3.6. The lighting system of claim 1 , wherein said emitted light has a color rendering index (CRI) greater ...

CIRCADIAN-FRIENDLY LED LIGHT SOURCE

Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80. 127.-. (canceled)28. A light source comprising:at least one first solid state light emitting device emitting a first light having a peak in a range 405 to 430 nm;one or more radiation sources for emitting second light of one or more wavelengths, at least one of said one or more radiation sources being a phosphor being excited by said first light; andwherein said light source is configured in at least a first way to emit a first emitted light comprising at least a portion of said first light and said second light, said first emitted light having a first spectral power distribution (SPD) in which the total power of said first SPD in the range of 440 to 500 nm is less than 5% of the total power of said first SPD in the range of 380 to 850 nm, said first emitted light also having a CCT in a range of about 2500° to about 5000° K, and a chromaticity being either within +/− five Du'v' points of a Planckian locus or below a Planckian locus.29. The light source of claim 28 , wherein said CCT of said first emitted light is one of about 2700° K claim 28 , about 3000° K claim 28 , about 3500° K claim 28 , about 4100° K claim 28 , or about 5000° K.30. The light source of claim 28 , wherein said first emitted light has a CRI Ra above 80.31. The light source of claim 28 , wherein said total power of said first SPD in the range of 440 to 500 nm is less than 1% of said total power of said first SPD in the range 380 to 850 nm.32. The light source of claim 28 , ...

CIRCADIAN-FRIENDLY LED LIGHT SOURCES

Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80. 1. (canceled)2. A method for controlling circadian stimulation (CS) in a location , said method comprising:(a) obtaining data on at least one measurable parameter in said location;(b) determining a first spectrum of light to increase CS, and a second spectrum of light to decrease said CS; and(c) causing at least one lighting device positioned at said location to switch between said first spectrum and said second spectrum in accordance with said data, wherein said lighting device comprises at least blue LEDs and violet LEDs, wherein the ratio of emissions from said blue LEDs to said violet LEDs is greater in said first spectrum than in said second spectrum.3. The method of claim 2 , wherein step (a) comprises using machine learning to learn first habits and second habits of a subject from said data claim 2 , and wherein step (c) comprises switching between said first spectrum and said second spectrum when said subject demonstrates said first habits or said second habits claim 2 , respectively.4. The method of claim 3 , wherein said first and second habits are correlated to time of day claim 3 , and wherein claim 3 , if said first habits or said second habits are demonstrated outside of their correlated time of day claim 3 , then said at least one lighting device is caused to emit said second spectrum or said first spectrum claim 3 , respectively.5. The method of claim 3 , wherein said at least one measurable parameter is selected from one or ...

SYSTEM AND METHOD FOR PROVIDING COLOR LIGHT SOURCES IN PROXIMITY TO PREDETERMINED WAVELENGTH CONVERSION STRUCTURES

An optical device includes a light source with at least two radiation sources, and at least two layers of wavelength-modifying materials excited by the radiation sources that emit radiation in at least two predetermined wavelengths. Embodiments include a first plurality of n radiation sources configured to emit radiation at a first wavelength. The first plurality of radiation sources are in proximity to a second plurality of m of radiation sources configured to emit radiation at a second wavelength, the second wavelength being shorter than the first wavelength. The ratio between m and n is predetermined. The disclosed optical device also comprises at least two wavelength converting layers such that a first wavelength converting layer is configured to absorb a portion of radiation emitted by the second radiation sources, and a second wavelength converting layer configured to absorb a portion of radiation emitted by the second radiation sources. 1. A light-emitting system comprising:at least one first light-emitting source configured to emit a first radiation, said first radiation being blue light having a first wavelength;at least one second light-emitting source configured to emit a second radiation, said second radiation being violet light having a second wavelength shorter than said first wavelength;one or more wavelength-converting materials disposed to absorb at least a portion of said first or second radiations, and configured to emit a converted radiation having one or more wavelengths longer than said first or second wavelengths such that said system emits emitted light comprising a blend of two or more of said first, second and converted radiations; andat least one driving circuit for selectively powering said at least one first and second light-emitting sources to adjust said blend of said emitted light.2. The system of claim 1 , wherein said at least one driving circuit is configured to be controlled to vary power to said at least one first light-emitting ...

LED LAMPS WITH IMPROVED QUALITY OF LIGHT

LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm. 1. (canceled)2. A light-emitting system comprising:at least one LED device comprising an n-type region, a light-emitting active region, and a p-type region, and emitting a first radiation characterized by a first wavelength in a first range;at least one first wavelength conversion material optically coupled to the at least one LED device, wherein the at least one first wavelength conversion material converts a part of the first radiation to a second radiation characterized by a second wavelength in a second range from about 500 nm to about 600 nm; andat least one second wavelength conversion material optically coupled to the at least one LED device, wherein the at least one second wavelength conversion material converts a part of the first radiation to a third radiation characterized by a third wavelength in a third range from about 600 to about 700 nm,wherein a light spectrum emitted by the light-emitting system has an R9 of at least 80 and is characterized by a spectral power distribution (SPD) in which a violet fraction of the SPD from about 390 nm to about 430 nm is at least at least 0.10.3. The light-emitting system of claim 2 , wherein said violet fraction of the SPD is at least 0.15.4. The light-emitting system of claim 2 , wherein R9 is at least 90.5. The light-emitting system of claim 4 , wherein R9 is at least 95.6. The light-emitting system of claim 2 , wherein said light-emitting system emits more than 500 lm7. An illumination system comprising:at least one LED device configured in a housing structure, wherein the at least one LED device comprises an n-type region, a light-emitting active region, and a p-type region;a wavelength conversion material optically coupled to the at least one LED device; anda power source electrically ...

Ordered interface texturing for a light emitting device

This method relates to the fabrication of semiconductor light-emitting devices having at least one ordered textured interface. Controlled interface texturing with an ordered pattern is provided on any or all interfaces of such a device to enhance light extraction from these interfaces and thus improve the performance of the device. Ordered interface texturing offers an improvement in light extraction by increasing the transmission of total optical power from the device into the ambient. This improvement is possible because ordered interface texturing can provide: 1) a reduction in Fresnel losses at the interface between the device and the ambient and, 2) a change or increase in the angular bandwidth of light which may transmit power into the ambient. This latter effect may be thought of a change or increase in the escape cone at an interface. Both effects can result in an overall increase in total light extraction efficiency for the LED.

Method of making a III-nitride light-emitting device with increased light generating capability

The present invention is an inverted III-nitride light-emitting device (LED) with enhanced total light generating capability. A large area device has an n-electrode that interposes the p-electrode metallization to provide low series resistance. The p-electrode metallization is opaque, highly reflective, and provides excellent current spreading. The p-electrode at the peak emission wavelength of the LED active region absorbs less than 25% of incident light per pass. A submount may be used to provide electrical and thermal connection between the LED die and the package. The submount material may be Si to provide electronic functionality such as voltage-compliance limiting operation. The entire device, including the LED-submount interface, is designed for low thermal resistance to allow for high current density operation. Finally, the device may include a high-refractive-index (n>1.8) superstrate.

Light-emitting III-nitride semiconductor device

Lichtemittierende III-Nitrid-Vorrichtung, die folgende Merkmale aufweist:eine erste Schicht eines ersten Leitfähigkeitstyps;eine erste Schicht eines zweiten Leitfähigkeitstyps;eine aktive Region (3);einen Tunnelübergang (100), wobei der Tunnelübergang folgende Merkmale aufweist:eine zweite Schicht eines ersten Leitfähigkeitstyps, die eine Dotiermittelkonzentration aufweist, die größer als die der ersten Schicht eines ersten Leitfähigkeitstyps ist; undeine zweite Schicht eines zweiten Leitfähigkeitstyps, die eine Dotiermittelkonzentration aufweist, die größer als die der ersten Schicht eines zweiten Leitfähigkeitstyps ist;eine dritte Schicht eines ersten Leitfähigkeitstyps;einen ersten Kontakt, der elektrisch mit der ersten Schicht eines ersten Leitfähigkeitstyps verbunden ist;einen zweiten Kontakt, der elektrisch mit der dritten Schicht eines ersten Leitfähigkeitstyps verbunden ist; wobei:der erste und der zweite Kontakt das gleiche Material aufweisen;das erste und das zweite Kontaktmaterial ein Reflexionsvermögen für Licht, das durch die aktive Region (3) emittiert wird, von mehr als 75 % aufweisen;die aktive Region (3) zwischen einer Schicht eines ersten Leitfähigkeitstyps und einer Schicht eines zweiten Leitfähigkeitstyps angeordnet ist;der Tunnelübergang (100) zwischen der ersten Schicht eines ersten Leitfähigkeitstyps und der dritten Schicht eines ersten Leitfähigkeitstyps angeordnet ist; undLicht von der Vorrichtung von einer Oberfläche gegenüber dem ersten und dem zweiten Kontakt extrahiert wird; undeine texturierte Schicht (12), die zwischen der dritten Schicht eines ersten Leitfähigkeitstyps und dem zweiten Kontakt angeordnet ist.

Package-integrated thin film LED

LED epitaxial layers (n-type, p-type, and active layers) are grown on a substrate. For each die, the n and p layers are electrically bonded to a package substrate that extends beyond the boundaries of the LED die such that the LED layers are between the package substrate and the growth substrate. The package substrate provides electrical contacts and conductors leading to solderable package connections. The growth substrate is then removed. Because the delicate LED layers were bonded to the package substrate while attached to the growth substrate, no intermediate support substrate for the LED layers is needed. The relatively thick LED epitaxial layer that was adjacent the removed growth substrate is then thinned and its top surface processed to incorporate light extraction features. There is very little absorption of light by the thinned epitaxial layer, there is high thermal conductivity to the package because the LED layers are directly bonded to the package substrate without any support substrate therebetween, and there is little electrical resistance between the package and the LED layers so efficiency (light output vs. power input) is high. The light extraction features of the LED layer further improves efficiency.

LED lamps with improved quality of light

LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm.

System and method for providing color light sources in proximity to predetermined wavelength conversion structures

An optical device includes a light source with at least two radiation sources, and at least two layers of wavelength-modifying materials excited by the radiation sources that emit radiation in at least two predetermined wavelengths. Embodiments include a first plurality of n radiation sources configured to emit radiation at a first wavelength. The first plurality of radiation sources are in proximity to a second plurality of m of radiation sources configured to emit radiation at a second wavelength, the second wavelength being shorter than the first wavelength. The ratio between m and n is predetermined. The disclosed optical device also comprises at least two wavelength converting layers such that a first wavelength converting layer is configured to absorb a portion of radiation emitted by the second radiation sources, and a second wavelength converting layer configured to absorb a portion of radiation emitted by the second radiation sources.

Apportioning optical projection paths in an LED lamp

LED illumination systems and techniques for apportioning optical projection paths in an LED lamp are disclosed.

Circadian friendly LED light source

Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80.

Method for growth of indium-containing nitride films

A method for growth of indium-containing nitride films is described, particularly a method for fabricating a gallium, indium, and nitrogen containing material. On a substrate having a surface region a material having a first indium-rich concentration is formed, followed by a second thickness of material having a first indium-poor concentration. Then a third thickness of material having a second indium-rich concentration is added to form a sandwiched structure which is thermally processed to cause formation of well-crystallized, relaxed material within a vicinity of a surface region of the sandwich structure.

Large area seed crystal for ammonothermal crystal growth and method of making

Large area seed crystals for ammonothermal GaN growth are fabricated by deposition or layer transfer of a GaN layer on a CTE-matched handle substrate. The sides and back of the handle substrate are protected from the ammonothermal growth environment by a coating comprising an adhesion layer, a diffusion barrier layer, and an inert layer. A patterned mask, also comprising an adhesion layer, a diffusion barrier layer, and an inert layer, may be provided over the GaN layer to allow for reduction of the dislocation density by lateral epitaxial growth.

III-nitride light-emitting device with increased light generating capability

The present invention is an inverted III-nitride light-emitting device (LED) with enhanced total light generating capability. A large area device has an n-electrode that interposes the p-electrode metallization to provide low series resistance. The p-electrode metallization is opaque, highly reflective, and provides excellent current spreading. The p-electrode at the peak emission wavelength of the LED active region absorbs less than 25% of incident light per pass. A submount may be used to provide electrical and thermal connection between the LED die and the package. The submount material may be Si to provide electronic functionality such as voltage-compliance limiting operation. The entire device, including the LED-submount interface, is designed for low thermal resistance to allow for high current density operation. Finally, the device may include a high-refractive-index (n>1.8) superstrate.

Luminescent ceramic for a light emitting device

A semiconductor light emitting device comprises a light emitting layer disposed between an n-type region and a p-type region is combined with a ceramic layer which is disposed in a path of light emitted by the light emitting layer. The light emitting device is supported by a submount or a host substrate. A heat extraction structure thermally couples the first ceramic layer to the submount or host substrate, respectively.

Luminescent ceramic for a light emitting device

A semiconductor light emitting device comprising a light emitting layer disposed between an n-type region and a p-type region is combined with a ceramic layer which is disposed in a path of light emitted by the light emitting layer. The ceramic layer is composed of or includes a wavelength converting material such as a phosphor. Luminescent ceramic layers according to embodiments of the invention may be more robust and less sensitive to temperature than prior art phosphor layers. In addition, luminescent ceramics may exhibit less scattering and may therefore increase the conversion efficiency over prior art phosphor layers.

Indium gallium nitride light emitting devices

InGaN-based light-emitting devices fabricated on an InGaN template layer are disclosed.

A1InGaP LED having reduced temperature dependence

To increase the lattice constant of AlInGaP LED layers to greater than the lattice constant of GaAs for reduced temperature sensitivity, an engineered growth layer is formed over a substrate, where the growth layer has a lattice constant equal to or approximately equal to that of the desired AlInGaP layers. In one embodiment, a graded InGaAs or InGaP layer is grown over a GaAs substrate. The amount of indium is increased during growth of the layer such that the final lattice constant is equal to that of the desired AlInGaP active layer. In another embodiment, a very thin InGaP, InGaAs, or AlInGaP layer is grown on a GaAs substrate, where the InGaP, InGaAs, or AlInGaP layer is strained (compressed). The InGaP, InGaAs, or AlInGaP thin layer is then delaminated from the GaAs and relaxed, causing the lattice constant of the thin layer to increase to the lattice constant of the desired overlying AlInGaP LED layers. The LED layers are then grown over the thin InGaP, InGaAs, or AlInGaP layer.

Light extraction from a semiconductor light-emitting device via chip shaping

The invention is a method for designing semiconductor light emitting devices such that the side surfaces (surfaces not parallel to the epitaxial layers) are formed at preferred angles relative to vertical (normal to the plane of the light-emitting active layer) to improve light extraction efficiency and increase total light output efficiency. Device designs are chosen to improve efficiency without resorting to excessive active area-yield loss due to shaping. As such, these designs are suitable for low-cost, high-volume manufacturing of semiconductor light-emitting devices with improved characteristics.

Buried reflectors for light emitters in epitaxial material and method for producing same

A buried reflector 50 in an epitaxial lateral growth layer forms a part of a light emitting device and allows for the fabrication of a semiconductor material that is substantially low in dislocation density. The laterally grown material is low in dislocation defect density where it is grown over the buried reflector making it suitable for high quality optical light emitting devices, and the embedded reflector eliminates the need for developing an additional reflector.

Light emitting devices having wafer bonded aluminum gallium indium nitride structures and mirror stacks

Light emitting devices having a vertical optical path, e.g. a vertical cavity surface emitting laser or a resonant cavity light emitting or detecting device, having high quality mirrors may be achieved using wafer bonding or metallic soldering techniques. The light emitting region interposes one or two reflector stacks containing dielectric distributed Bragg reflectors (DBRs). The dielectric DBRs may be deposited or attached to the light emitting device. A host substrate of GaP, GaAs, InP, or Si is attached to one of the dielectric DBRs. Electrical contacts are added to the light emitting device.

Strain-controlled iii-nitride light emitting device

Contact for a semiconductor light emitting device

Low profile side emitting led

【課題】低プロファイルの側面放射ＬＥＤを提供すること。 【解決手段】低プロファイルの側面放射ＬＥＤについて説明され、ここで、全ての光が、光を生成する活性層の表面とほぼ平行に比較的狭い角度内で効率的に放射される。このＬＥＤは、ＬＣＤを背面から照らすための非常に薄いバックライトの生成を可能にする。一実施形態において、ＬＥＤは、ＬＥＤの同じ側にｎ電極及びｐ電極を有するフリップ・チップ型であり、ＬＥＤは、サブマウント上に電極側を下にしてマウントされる。リフレクタが、ＬＥＤの上面に設けられるので、リフレクタに当たる光が、再び活性層に向けて反射され、最終的にＬＥＤの側部を通って出ていく。効率を向上させるために、導波路層及び／又は１つ又はそれ以上の蛍光体層が、半導体層とリフレクタとの間に堆積され、側面放射領域を増加させる。０．２ｍｍから０．４ｍｍまでの間の厚さを有する側面放射ＬＥＤを形成することができる。 【選択図】図１

Iii-nitride light emitting device with reduced strain light emitting layer

In accordance with embodiments of the invention, strain is reduced in the light emitting layer of a Ill-nitride device by including a strain-relieved layer in the device. The surface on which the strain-relieved layer is grown is configured such that strain-relieved layer can expand laterally and at least partially relax. In some embodiments of the invention, the strain-relieved layer is grown over a textured semiconductor layer or a mask layer. In some embodiments of the invention, the strain-relieved layer is group of posts of semiconductor material.

Silicone based reflective underfill and thermal coupler for flip chip led

Method of forming a composite substrate and growing a III-V light emitting device over the composite substrate

A method according to embodiments of the invention includes providing a substrate comprising a host and a seed layer bonded to the host. The seed layer comprises a plurality of regions. A semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region is grown on the substrate. A top surface of a semiconductor layer grown on the seed layer has a lateral extent greater than each of the plurality of seed layer regions.

Light emitting diodes with improved light extraction efficiency

Light emitting devices with improved light extraction efficiency are provided. The light emitting devices have a stack of layers including semiconductor layers comprising an active region. The stack is bonded to a transparent lens having a refractive index for light emitted by the active region preferably greater than about 1.5, more preferably greater than about 1.8. A method of bonding a transparent lens to a light emitting device having a stack of layers including semiconductor layers comprising an active region includes elevating a temperature of the lens and the stack and applying a pressure to press the lens and the stack together. Bonding a high refractive index lens to a light emitting device improves the light extraction efficiency of the light emitting device by reducing loss due to total internal reflection. Advantageously, this improvement can be achieved without the use of an encapsulant.

Circadian-friendly LED light sources

Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80.

Mount for a Semiconductor Light Emitting Device

A mount for a semiconductor device includes a carrier, at least two metal leads disposed on a bottom surface of the carrier, and a cavity extending through a thickness of the carrier to expose a portion of the top surfaces of the metal leads. A semiconductor light emitting device is positioned in the cavity and is electrically and physically connected to the metal leads. The carrier may be, for example, silicon, and the leads may be multilayer structures, for example a thin gold layer connected to a thick copper layer.

Strain-controlled Ⅲ-nitride light emitting device

III-Phospide and III-Arsenide flip chip light-emitting devices

A light-emitting semiconductor device includes a stack of layers including an active region. The active region includes a semiconductor selected from the group consisting of III-Phosphides, III-Arsenides, and alloys thereof. A superstrate substantially transparent to light emitted by the active region is disposed on a first side of the stack. First and second electrical contacts electrically coupled to apply a voltage across the active region are disposed on a second side of the stack opposite to the first side. In some embodiments, a larger fraction of light emitted by the active region exits the stack through the first side than through the second side. Consequently, the light-emitting semiconductor device may be advantageously mounted as a flip chip to a submount, for example.

Light emitting diodes with improved light extraction efficiency

Method for manufacturing a light-emitting device

Compliant bonding structures for semiconductor devices

A compliant bonding structure is disposed between a semiconductor light emitting device and a mount (40). When the semiconductor light emitting device is attached to the mount, for example by providing pressure, heat, and/or ultrasonic energy to the semiconductor light emitting device, the compliant bonding structure collapses to partially fill a space between the semiconductor light emitting device and the mount. In some embodiments, the compliant bonding structure is plurality of metal bumps (32) that undergo plastic deformation during bonding. In some embodiments, the compliant bonding structure is a porous metal layer (46).

Photonic crystal light emitting device

Substrate for growing an iii-v light-emitting device and structure for light emitting device

Light emitting element with improved light extraction through chip molds and methods of manufacturing the same

Semiconductor light emitting device and method of fabrication

A light-emitting device includes: a semiconductor structure formed on one side of a substrate, the semiconductor structure having a plurality of semiconductor layers and an active region within the layers; and first and second conductive electrodes contacting respectively different semiconductor layers of the structure; the substrate comprising a material having a refractive index n > 2.0 and light absorption coefficient α, at the emission wavelength of the active region, of α > 3 cm -1 . In a preferred embodiment, the substrate material has a refractive index n > 2.3, and the light absorption coefficient, α, of the substrate material is α < 1 cm -1 .

Semiconductor light emitting devices with graded composition light emitting layers

Photonic crystal light emitting device

A photonic crystal structure is formed in an n-type layer of a III-nitride light emitting device. In some embodiments, the photonic crystal n-type layer (7) is formed on a tunnel junction. The device includes a first layer of first conductivity type (108), a first layer of second conductivity type (116), and an active region (112) separating the first layer of first conductivity type (108) from the first layer of second conductivity type (116). The tunnel junction includes a second layer of first conductivity type (6) and a second layer of second conductivity type (5) and separates the first layer of first conductivity type (108) from a third layer of first conductivity type (7). A photonic crystal structure is formed in the third layer of first conductivity type (7).

Method for manufacturing light emitting device

本發明揭示一種基板，其包括一主體與一接合至該主體之種晶層，而一包括置放於一n型區域與一p型區域間之發光層的半導體結構係長於該種晶層上。於部分具體實施例中，一接合層會將該主體接合至該種晶層。該種晶層可比用以使該半導體結構之壓受力鬆弛的關鍵厚度薄，使得該半導體結構之壓受力係藉由該種晶層中所形成之位錯，或藉由該種晶層與該接合層(介於該等二層之間的介面)之間的滑動而得以釋放。於部分具體實施例中，該主體可藉由將該接合層蝕刻掉而與該半導體結構及種晶層分隔開來。

POWER LIGHT DIODE AND METHOD WITH POWER DENSITY OPERATION

Eine bei einer Wellenlänge von 390–415 nm emittierende Leuchtdiode weist ein gallium- und stickstoffhaltiges Grundmaterial mit einem aktiven Bereich auf. Das Bauelement weist eine Stromdichte von mehr als etwa 175 A/cm2 und eine externe Quantenausbeute mit einem Roll-off von weniger als 5% der absoluten Effizienz auf.

Iii-nitride light emitting device with reduced strain light emitting layer

In accordance with embodiments of the invention, strain is reduced in the light emitting layer of a Ill-nitride device by including a strain-relieved layer in the device. The surface on which the strain-relieved layer is grown is configured such that strain-relieved layer can expand laterally and at least partially relax. In some embodiments of the invention, the strain-relieved layer is grown over a textured semiconductor layer or a mask layer. In some embodiments of the invention, the strain-relieved layer is group of posts of semiconductor material.

Resonant cavity III-nitride light emitting devices fabbricated by growth substrate removal

A semiconductor light-emitting device includes an n-type region, a p-type region, and light-emitting region disposed between the n- and p-type regions. The n-type, p-type, and light emitting regions form a cavity having a top surface and a bottom surface. Both the top surface and the bottom surface of the cavity may have a rough surface. For example, the surface may have a plurality of peaks separated by a plurality of valleys. In some embodiments, the thickness of the cavity is kept constant by incorporating an etch-stop layer into the device, then thinning the layers of the device by a process that terminates on the etch-stop layer.

Silicone based reflective underfill and thermal coupler for flip chip LED