Abstract: A temperature stable (color and efficiency) III-nitride based amber (585 nm) light-emitting diode is based on a novel hybrid nanowire-planar structure. The arrays of GaN nanowires enable radial InGaN/GaN quantum well LED structures with high indium content and high material quality. The high efficiency and temperature stable direct yellow and red phosphor-free emitters enable high efficiency white LEDs based on the RGYB color-mixing approach.

Abstract: Structures are incorporated into a semiconductor light emitting device which may increase the extraction of light emitted at glancing incidence angles. In some embodiments, the device includes a low index material that directs light away from the metal contacts by total internal reflection. In some embodiments, the device includes extraction features such as cavities in the semiconductor structure which may extract glancing angle light directly, or direct the glancing angle light into smaller incidence angles which are more easily extracted from the device.

Abstract: Structures are incorporated into a semiconductor light emitting device which may increase the extraction of light emitted at glancing incidence angles. In some embodiments, the device includes a low index material that directs light away from the metal contacts by total internal reflection. In some embodiments, the device includes extraction features such as cavities in the semiconductor structure which may extract glancing angle light directly, or direct the glancing angle light into smaller incidence angles which are more easily extracted from the device.

Abstract: 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.

Abstract: 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.

Abstract: A semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region and a photonic crystal formed within or on a surface of the semiconductor structure 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.

Abstract: Structures are incorporated into a semiconductor light emitting device which may increase the extraction of light emitted at glancing incidence angles. In some embodiments, the device includes a low index material that directs light away from the metal contacts by total internal reflection. In some embodiments, the device includes extraction features such as cavities in the semiconductor structure which may extract glancing angle light directly, or direct the glancing angle light into smaller incidence angles which are more easily extracted from the device.

Abstract: A semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region is grown over a porous III-nitride region. A III-nitride layer comprising InN is disposed between the light emitting layer and the porous III-nitride region. Since the III-nitride layer comprising InN is grown on the porous region, the III-nitride layer comprising InN may be at least partially relaxed, i.e. the III-nitride layer comprising InN may have an in-plane lattice constant larger than an in-plane lattice constant of a conventional GaN layer grown on sapphire.

Abstract: Structures are incorporated into a semiconductor light emitting device which may increase the extraction of light emitted at glancing incidence angles. In some embodiments, the device includes a low index material that directs light away from the metal contacts by total internal reflection. In some embodiments, the device includes extraction features such as cavities in the semiconductor structure which may extract glancing angle light directly, or direct the glancing angle light into smaller incidence angles which are more easily extracted from the device.

Abstract: A semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region is grown over a porous III-nitride region. A III-nitride layer comprising InN is disposed between the light emitting layer and the porous III-nitride region. Since the III-nitride layer comprising InN is grown on the porous region, the III-nitride layer comprising InN may be at least partially relaxed, i.e. the III-nitride layer comprising InN may have an in-plane lattice constant larger than an in-plane lattice constant of a conventional GaN layer grown on sapphire.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A semiconductor structure formed on a growth substrate and including a light emitting layer disposed between an n-type region and a p-type region is attached to a carrier by a connection that supports the semiconductor structure sufficiently to permit removal of the growth substrate. In some embodiments, the semiconductor structure is a flip chip device. The semiconductor structure may be attached to the carrier by, for example, a metal bond that supports almost the entire lateral extent of the semiconductor structure, or by interconnects such as solder or gold stud bumps. An underfill material which supports the semiconductor structure is introduced in any spaces between the interconnects. The underfill material may be a liquid that is cured to form a rigid structure. The growth substrate may then be removed without causing damage to the semiconductor structure.

Abstract: A light emitting device includes a structure with a light emitting region disposed between an n-type region and a p-type region. A plurality of holes in the structure, which form a photonic crystal, are formed in a first region of the structure corresponding to a first portion of the light emitting region. A second region of the structure corresponding to a second portion of the light emitting region is free of holes. The device is configured such that when forward biased, current is injected in the second region and the first region is substantially free of current.

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: 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.

Abstract: Structures are incorporated into a semiconductor light emitting device which may increase the extraction of light emitted at glancing incidence angles. In some embodiments, the device includes a low index material that directs light away from the metal contacts by total internal reflection. In some embodiments, the device includes extraction features such as cavities in the semiconductor structure which may extract glancing angle light directly, or direct the glancing angle light into smaller incidence angles which are more easily extracted from the device.

Abstract: A semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region is grown over a porous III-nitride region. A III-nitride layer comprising InN is disposed between the light emitting layer and the porous III-nitride region. Since the III-nitride layer comprising InN is grown on the porous region, the III-nitride layer comprising InN may be at least partially relaxed, i.e. the III-nitride layer comprising InN may have an in-plane lattice constant larger than an in-plane lattice constant of a conventional GaN layer grown on sapphire.

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.