Abstract: A semiconductor sensor, solar cell or emitter, or a precursor therefor, has a substrate and one or more textured semiconductor layers deposited onto the substrate. The textured layers enhance light extraction or absorption. Texturing in the region of multiple quantum wells greatly enhances internal quantum efficiency if the semiconductor is polar and the quantum wells are grown along the polar direction. Electroluminescence of LEDs of the invention is dichromatic, and results in variable color LEDs, including white LEDs, without the use of phosphor.

Abstract: A semiconductor emitter, or a precursor therefor, has a substrate and one or more textured semiconductor layers deposited onto the substrate in a nonpolar orientation. The textured layers enhance light extraction, and the use of nonpolar orientation greatly enhances internal quantum efficiency compared to conventional devices. Both the internal and external quantum efficiencies of emitters of the invention can be 70-80% or higher. The invention provides highly efficient light emitting diodes suitable for solid state lighting.

Abstract: A semiconductor sensor, solar cell or emitter or a precursor therefore having a substrate and textured semiconductor layer deposited onto the substrate. The layer can be textured as grown on the substrate or textured by replicating a textured substrate surface. The substrate or first layer is then a template for growing and texturing other semiconductor layers from the device. The textured layers are replicated to the surface from the substrate to enhance light extraction or light absorption. Multiple quantum wells, comprising several barrier and quantum well layers, are deposited as alternating textured layers. The texturing in the region of the quantum well layers greatly enhances internal quantum efficiency if the semiconductor is polar and the quantum wells are grown along the polar direction. This is the case in nitride semiconductors grown along the polar [0001] or [000-1] directions.

Abstract: An epitaxial growth system comprises a housing around an epitaxial growth chamber. A substrate support is located within the growth chamber. A gallium source introduces gallium into the growth chamber and directs the gallium towards the substrate. An activated nitrogen source introduces activated nitrogen into the growth chamber and directs the activated nitrogen towards the substrate. The activated nitrogen comprises ionic nitrogen species and atomic nitrogen species. An external magnet and/or an exit aperture control the amount of atomic nitrogen species and ionic nitrogen species reaching the substrate.

Abstract: Films of III-nitride for semiconductor device growth are planarized using an etch-back method. The method includes coating a III-nitride surface having surface roughness features in the micron range with a sacrificial planarization material such as an appropriately chose photoresist. The sacrificial planarization material is then etched together with the III-nitride roughness features using dry etch methods such as inductivel coupled plasma reactive ion etching. By closely matching the etch rates of the sacrificial planarization material and the III-nitride material, a planarized III-nitride surface is achieved. The etch-back process together with a high temperature annealing process yields a planarize III-nitride surface with surface roughness features reduced to the nm range. Planarized III-nitride, e.g., GaN, substrates and devices containing them are also provided.

Abstract: An etched grooved GaN-based permeable-base transistor structure is disclosed, along with a method for fabrication of same.

Abstract: An etched grooved GaN-based permeable-base transistor structure is disclosed, along with a method for fabrication of same.

Abstract: An epitaxial growth system comprises a housing around an epitaxial growth chamber. A substrate support is located within the growth chamber. A gallium source introduces gallium into the growth chamber and directs the gallium towards the substrate. An activated nitrogen source introduces activated nitrogen into the growth chamber and directs the activated nitrogen towards the substrate. The activated nitrogen comprises ionic nitrogen species and atomic nitrogen species. An external magnet and/or an exit aperture control the amount of atomic nitrogen species and ionic nitrogen species reaching the substrate.

Abstract: An epitaxial growth system comprises a housing around an epitaxial growth chamber. A substrate support is located within the growth chamber. A gallium source introduces gallium into the growth chamber and directs the gallium towards the substrate. An activated nitrogen source introduces activated nitrogen into the growth chamber and directs the activated nitrogen towards the substrate. The activated nitrogen comprises ionic nitrogen species and atomic nitrogen species. An external magnet and/or an exit aperture control the amount of atomic nitrogen species and ionic nitrogen species reaching the substrate.

Abstract: High quality epitaxial layers of monocrystalline materials can be grown overlying monocrystalline substrates such as SiC or sapphire by forming a compliant substrate for the growing the monocrystalline layers. Devices and methods for fabricating silicon carbide based heterojunction bipolar devices such as transistors and diodes. These devices are suitable for high power and/or high speed and/or high temperature electronic applications.

Abstract: An epitaxial growth system comprises a housing around an epitaxial growth chamber. A substrate support is located within the growth chamber. A gallium source introduces gallium into the growth chamber and directs the gallium towards the substrate. An activated nitrogen source introduces activated nitrogen into the growth chamber and directs the activated nitrogen towards the substrate. The activated nitrogen comprises ionic nitrogen species and atomic nitrogen species. An external magnet and/or an exit aperture control the amount of atomic nitrogen species and ionic nitrogen species reaching the substrate.

Abstract: An epitaxial growth system comprises a housing around an epitaxial growth chamber. A substrate support is located within the growth chamber. A gallium source introduces gallium into the growth chamber and directs the gallium towards the substrate. An activated nitrogen source introduces activated nitrogen into the growth chamber and directs the activated nitrogen towards the substrate. The activated nitrogen comprises ionic nitrogen species and atomic nitrogen species. An external magnet and/or an exit aperture control the amount of atomic nitrogen species and ionic nitrogen species reaching the substrate.

Abstract: A piezoresistor having a base substrate with a quantum well structure formed on the base substrate. The quantum well structure includes at least one quantum well layer bounded by barrier layers. The barrier layers are formed from a material having a larger bandgap than the at least one quantum well layer.

Abstract: A piezoresistor having a base substrate with a quantum well structure formed on the base substrate. The quantum well structure includes at least one quantum well layer bounded by barrier layers. The barrier layers are formed from a material having a larger bandgap than the at least one quantum well layer.

Abstract: A piezoresistor having a base substrate with a quantum well structure formed on the base substrate. The quantum well structure includes at least one quantum well layer bounded by barrier layers. The barrier layers are formed from a material having a larger bandgap than the at least one quantum well layer.

Abstract: This invention relates to a method of preparing highly insulating GaN single crystal films in a molecular beam epitaxial growth chamber. A single crystal substrate is provided with the appropriate lattice match for the desired crystal structure of GaN. A molecular beam source of Ga and source of activated atomic and ionic nitrogen are provided within the growth chamber. The desired film is deposited by exposing the substrate to Ga and nitrogen sources in a two step growth process using a low temperature nucleation step and a high temperature growth step. The low temperature process is carried out at 100-400.degree. C. and the high temperature process is carried out at 600-900.degree. C. The preferred source of activated nitrogen is an electron cyclotron resonance microwave plasma.

Abstract: A bandpass photodetector using a III-V nitride and having predetermined electrical properties. The bandpass photodetector detects electromagnetic radiation between a lower transition wavelength and an upper transition wavelength. That detector comprises two low pass photodetectors. The response of the two low pass photodetectors is subtracted to yield a response signal.

Abstract: An epitaxial growth system comprises a housing around an epitaxial growth chamber. A substrate support is located within the growth chamber. A gallium source introduces gallium into the growth chamber and directs the gallium towards the substrate. An activated nitrogen source introduces activated nitrogen into the growth chamber and directs the activated nitrogen towards the substrate. The activated nitrogen comprises ionic nitrogen species and atomic nitrogen species. An external magnet and/or an exit aperture control the amount of atomic nitrogen species and ionic nitrogen species reaching the substrate.

Abstract: This invention relates to a method of preparing highly insulating GaN single crystal films in a molecular beam epitaxial growth chamber. A single crystal substrate is provided with the appropriate lattice match for the desired crystal structure of GaN. A molecular beam source of Ga and source of activated atomic and ionic nitrogen are provided within the growth chamber. The desired film is deposited by exposing the substrate to Ga and nitrogen sources in a two step growth process using a low temperature nucleation step and a high temperature growth step. The low temperature process is carried out at 100-400.degree. C. and the high temperature process is carried out at 600-900.degree. C. The preferred source of activated nitrogen is an electron cyclotron resonance microwave plasma.

Abstract: An etched grooved GaN-based permeable-base transistor structure is disclosed, along with a method for fabrication of same.