Abstract: A semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region is attached to a compound substrate including a host which provides mechanical support to the device and a ceramic layer including a luminescent material. In some embodiments the compound substrate includes a crystalline seed layer on which the semiconductor structure is grown. The ceramic layer is disposed between the seed layer and the host. In some embodiments, the compound substrate is attached to the semiconductor structure compound substrate is spaced apart from the semiconductor structure and does not provide mechanical support to the structure. In some embodiments, the ceramic layer has a thickness less than 500 ?m.

Abstract: 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 n-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.

Abstract: Devices and techniques for fabricating InAlGaN light-emitting devices are described that result from the removal of light-emitting layers from the sapphire growth substrate. In several embodiments, techniques for fabricating a vertical InAlGaN light-emitting diode structure that result in improved performance and or cost-effectiveness are described. Furthermore, metal bonding, substrate liftoff, and a novel RIE device separation technique are employed to efficiently produce vertical GaN LEDs on a substrate chosen for its thermal conductivity and ease of fabrication.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.