Abstract: A method comprises providing a substrate comprising an n-type Al/In/GaN semiconductor material. A surface of the substrate is dry-etched to form a trench therein and cause dry-etch damage to remain on the surface. The surface of the substrate is immersed in an electrolyte solution and illuminated with above bandgap light having a wavelength that generates electron-hole pairs in the n-type Al/In/GaN semiconductor material, thereby photoelectrochemically etching the surface to remove at least a portion of the dry-etch damage.

Abstract: A vertical gallium nitride (GaN) PN diode uses epitaxial growth of a thick drift region with a very low carrier concentration and a carefully designed multi-zone junction termination extension to achieve high voltage blocking and high-power efficiency. An exemplary large area (1 mm2) diode had a forward pulsed current of 3.5 A, an 8.3 m?-cm2 specific on-resistance, and a 5.3 kV reverse breakdown. A smaller area diode (0.063 mm2) was capable of 6.4 kV breakdown with a specific on-resistance of 10.2 m?-cm2, when accounting for current spreading through the drift region at a 45° angle.

Abstract: A method comprises providing a substrate comprising an n-type Al/In/GaN semiconductor material. A surface of the substrate is dry-etched to form a trench therein and cause dry-etch damage to remain on the surface. The surface of the substrate is immersed in an electrolyte solution and illuminated with above bandgap light having a wavelength that generates electron-hole pairs in the n-type Al/In/GaN semiconductor material, thereby photoelectrochemically etching the surface to remove at least a portion of the dry-etch damage.

Abstract: A method comprises providing a substrate comprising an n-type Al/In/GaN semiconductor material. A surface of the substrate is dry-etched to form a trench therein and cause dry-etch damage to remain on the surface. The surface of the substrate is immersed in an electrolyte solution and illuminated with above bandgap light having a wavelength that generates electron-hole pairs in the n-type Al/In/GaN semiconductor material, thereby photoelectrochemically etching the surface to remove at least a portion of the dry-etch damage.

Abstract: A method comprises providing a substrate comprising an n-type Al/In/GaN semiconductor material. A surface of the substrate is dry-etched to form a trench therein and cause dry-etch damage to remain on the surface. The surface of the substrate is immersed in an electrolyte solution and illuminated with above bandgap light having a wavelength that generates electron-hole pairs in the n-type Al/In/GaN semiconductor material, thereby photoelectrochemically etching the surface to remove at least a portion of the dry-etch damage.

Abstract: Methods are provided for fabricating a HEMT (high-electron-mobility transistor) that involve sequential epitaxial growth of III-nitride channel and barrier layers, followed by epitaxial regrowth of further III-nitride material through a window in a mask layer. The regrowth takes place on the barrier layer, only in the access region or regions. Devices made according to the disclosed methods are also provided.

Abstract: Methods are provided for fabricating a HEMT (high-electron-mobility transistor) that involve sequential epitaxial growth of III-nitride channel and barrier layers, followed by epitaxial regrowth of further III-nitride material through a window in a mask layer. In examples, the regrowth takes place over exposed portions of the channel layer in the source and drain regions of the device, and the regrown material has a composition different from the barrier layer. In other examples, the regrowth takes place on the barrier layer, only in the access region or regions. Devices made according to the disclosed methods are also provided.

Abstract: A diode includes a second semiconductor layer over a first semiconductor layer. The diode further includes a third semiconductor layer over the second semiconductor layer, where the third semiconductor layer includes a first semiconductor element over the second semiconductor layer. The third semiconductor layer additionally includes a second semiconductor element over the second semiconductor layer, wherein the second semiconductor element surrounds the first semiconductor element. Further, the third semiconductor layer includes a third semiconductor element over the second semiconductor element. Furthermore, a hole concentration of the second semiconductor element is less than a hole concentration of the first semiconductor element.

Abstract: A vertical III-nitride thin-film power diode can hold off high voltages (kV's) when operated under reverse bias. The III-nitride device layers can be grown on a wider bandgap template layer and growth substrate, which can be removed by laser lift-off of the epitaxial device layers grown thereon.

Abstract: Selective layer disordering in a doped III-nitride superlattice can be achieved by depositing a dielectric capping layer on a portion of the surface of the superlattice and annealing the superlattice to induce disorder of the layer interfaces under the uncapped portion and suppress disorder of the interfaces under the capped portion. The method can be used to create devices, such as optical waveguides, light-emitting diodes, photodetectors, solar cells, modulators, laser, and amplifiers.

Abstract: Ultraviolet light-emitting diodes with tailored AlGaN quantum wells can achieve high extraction efficiency. For efficient bottom light extraction, parallel polarized light is preferred, because it propagates predominately perpendicular to the QW plane and into the typical and more efficient light escape cones. This is favored over perpendicular polarized light that propagates along the QW plane which requires multiple, lossy bounces before extraction. The thickness and carrier density of AlGaN QW layers have a strong influence on the valence subband structure, and the resulting optical polarization and light extraction of ultraviolet light-emitting diodes. At Al>0.3, thinner QW layers (<2.5 nm are preferred) result in light preferentially polarized parallel to the QW plane. Also, active regions consisting of six or more QWs, to reduce carrier density, and with thin barriers, to efficiently inject carriers in all the QWs, are preferred.

Abstract: A p-type superlattice is used to laterally inject holes into an III-nitride multiple quantum well active layer, enabling efficient light extraction from the active area. Laterally-injected light-emitting diodes and laser diodes can enable brighter, more efficient devices that impact a wide range of wavelengths and applications. For UV wavelengths, applications include fluorescence-based biological sensing, epoxy curing, and water purification. For visible devices, applications include solid state lighting and projection systems.

Abstract: A p-type superlattice is used to laterally inject holes into an III-nitride multiple quantum well active layer, enabling efficient light extraction from the active area. Laterally-injected light-emitting diodes and laser diodes can enable brighter, more efficient devices that impact a wide range of wavelengths and applications. For UV wavelengths, applications include fluorescence-based biological sensing, epoxy curing, and water purification. For visible devices, applications include solid state lighting and projection systems.

Abstract: Selective layer disordering in a doped III-nitride superlattice can be achieved by depositing a dielectric capping layer on a portion of the surface of the superlattice and annealing the superlattice to induce disorder of the layer interfaces under the uncapped portion and suppress disorder of the interfaces under the capped portion. The method can be used to create devices, such as optical waveguides, light-emitting diodes, photodetectors, solar cells, modulators, laser, and amplifiers.

Abstract: A method for impurity-induced disordering in III-nitride materials comprises growing a III-nitride heterostructure at a growth temperature and doping the heterostructure layers with a dopant during or after the growth of the heterostructure and post-growth annealing of the heterostructure. The post-growth annealing temperature can be sufficiently high to induce disorder of the heterostructure layer interfaces.

Abstract: A denticulated Group III nitride structure that is useful for growing AlxGa1-xN to greater thicknesses without cracking and with a greatly reduced threading dislocation (TD) density.

Abstract: A denticulated Group III nitride structure that is useful for growing AlxGa1-xN to greater thicknesses without cracking and with a greatly reduced threading dislocation (TD) density.

Abstract: A frequency-doubled semiconductor vertical-external-cavity surface-emitting laser (VECSEL) is disclosed for generating light at a wavelength in the range of 300-550 nanometers. The VECSEL includes a semiconductor multi-quantum-well active region that is electrically or optically pumped to generate lasing at a fundamental wavelength in the range of 600-1100 nanometers. An intracavity nonlinear frequency-doubling crystal then converts the fundamental lasing into a second-harmonic output beam. With optical pumping with 330 milliWatts from a semiconductor diode pump laser, about 5 milliWatts or more of blue light can be generated at 490 nm. The device has applications for high-density optical data storage and retrieval, laser printing, optical image projection, chemical-sensing, materials processing and optical metrology.

Abstract: A new class of fabrication methods for embedded distributed grating structures is claimed, together with optical devices which include such structures. These new methods are the only known approach to making defect-free high-dielectric contrast grating structures, which are smaller and more efficient than are conventional grating structures.

Abstract: An InGaAsN/GaAs semiconductor p-n heterojunction is disclosed for use in forming a 0.95-1.2 eV bandgap photodetector with application for use in high-efficiency multi-junction solar cells. The InGaAsN/GaAs p-n heterojunction is formed by epitaxially growing on a gallium arsenide (GaAs) or germanium (Ge) substrate an n-type indium gallium arsenide nitride (InGaAsN) layer having a semiconductor alloy composition InxGa1−xAs1−yNy with 0<x≦0.2 and 0<y≦0.04 and a p-type GaAs layer, with the InGaAsN and GaAs layers being lattice-matched to the substrate. The InGaAsN/GaAs p-n heterojunction can be epitaxially grown by either molecular beam epitaxy (MBE) or metalorganic chemical vapor deposition (MOCVD). The InGaAsN/GaAs p-n heterojunction provides a high open-circuit voltage of up to 0.62 volts and an internal quantum efficiency of >70%.