Abstract: Methods, devices, and compositions of matter related to high efficiency InGaN-based photovoltaic devices. The disclosed synthesis of semiconductor heterostructures may be exploited to produce higher efficiency, longer lasting, photovoltaic cells.

Abstract: Methods, devices, and compositions of matter related to high efficiency InGaN-based photovoltaic devices. The disclosed synthesis of semiconductor heterostructures may be exploited to produce higher efficiency, longer lasting, photovoltaic cells.

Abstract: A semiconductor structure (10, 10?, 70, 80) includes a light emitter (12, 72) carried by a support structure (11). The light emitter (12, 72) includes a base region (24, 76) with a sloped sidewall (12a, 12b) and a light emitting region (25, 77) positioned thereon. The light emitting (25, 77) region includes a nitride semiconductor alloy having a composition that is different in a first region (26, 95) near the support structure (11) compared to a second region (27, 96) away from the support structure (11).

Abstract: A simple, inexpensive method of producing in bulk a doped metal nitride powder that exhibits a high luminescent efficiency, by first forming a metal-dopant alloy and then reacting the alloy with high purity ammonia under controlled conditions in a reactor. The resulting doped metal nitride powders will exhibit a luminescent efficiency that greatly exceeds that seen in pure undoped GaN powders, doped GaN thin films, and ZnS powders.

Abstract: A method of producing high quality GaN powder by combining high purity gallium and high purity ammonia in a tube reactor under controlled conditions. A reaction between the ammonia and gallium under the controlled conditions produces a porous gallium melt and to a full reaction, yielding high purity crystalline GaN powders with a stoichiometric nitrogen concentration and a hexagonal wurtzite structure.

Abstract: A method of producing high quality GaN powder by combining high purity gallium and high purity ammonia in a tube reactor under controlled conditions. A reaction between the ammonia and gallium under the controlled conditions produces a porous gallium melt and to a full reaction, yielding high purity crystalline GaN powders with a stoichiometric nitrogen concentration and a hexagonal wurtzite structure.

Abstract: The present invention relates to electronic devices formed in crystallites of III-V nitride materials. Specifically, the present invention simplifies the processing technology required for the fabrication of high-performance electronic devices in III-V nitride materials.

Abstract: Methods for defect-free impurity-induced laser disordering (IILD) of AlGaInP and AlGaAs heterostructures. Phosphorus-doped or As-doped films are used in which silicon serves as a diffusion source and silicon nitride acts as a barrier for selective IILD. High-performance, index-guided (AlGa).sub.0.5 In.sub.0.5 P lasers may be fabricated with this technique, analogous to those made in the AlGaAs material system. The deposition of the diffusion source films preferably is carried out in a low pressure reactor. Also disclosed is a scheme for reducing or eliminating phosphorus overpressure during silicon diffusion into III-V semiconducting material by adding a pre-diffusion anneal step. Defects produced during intermixing are also reduced using a GaInP or GaInP/GaAs cap.

Abstract: A buried-layer semiconductor structure solving the problem of defect and dislocation generation which typically results when impurity induced layer disordering occurs across interfaces where there are changes in both the column III and the column V constituents in the manufacture of III-V compound semiconductors, for use, for example, in lasers. The structure is characterized by a thin buried active layers entirely bounded by thick layers on a substrate. Defect generation is avoided by maintaining the thin layer below a critical thickness and lattice matching the thick layers to the substrate.As a further feature, the problem of relatively poor thermal conductivity in AlGaInP based laser structures is avoided by minimizing the amount of AlGaInP material contained in the laser structure, restricting these materials only to the critical active layers, and using AlGaAs for the majority of the optical guiding and carrier confining layers.

Abstract: A multilayered reflector structure deposited on the light emitting surface of a semiconductor electroluminescent device and consecutively comprising a layer of low refractive index material, a layer of intermediate refractive index material and a layer of high refractive index material. Ablative means remove and form an aperture in the outer high index layer at the region of optical radiation emission from said device whereby the level of reflectivity is highest at the center of the aperture as compared to structure regions adjacent to the aperture. In this manner, fundamental mode stabilization may be achieved. Also disclosed is a nonablated three layered reflector structure.