An epitaxial structure of a nonpolar AlGaN-based deep-ultraviolet (DUV) photoelectric detector and a preparation method thereof are provided. The epitaxial structure of the nonpolar AlGaN-based DUV photoelectric detector includes a nonpolar AlN buffer layer, a nonpolar Al.sub.0.15Ga.sub.0.85N buffer layer, and a nonpolar Al.sub.0.7Ga.sub.0.3N epitaxial layer that are sequentially grown on a LaAlO.sub.3 substrate. The LaAlO.sub.3 substrate takes a (100) plane as an epitaxial plane, and AlN[11-20] as an epitaxial growth direction. With the LaAlO.sub.3 substrate, the epitaxial structure reduces dislocations and stresses between the substrate and the epitaxial buffer layer. By designing two AlGaN epitaxial buffer layers with different components, the epitaxial structure reduces a dislocation density and a surface roughness of the nonpolar AlGaN epitaxial layer, further accelerates photoresponse and detectivity of the detector, and enhances overall performance of the nonpolar AlGaN-based DUV photoelectric detector.

One aspect of the present invention is a double sided hybrid crystal structure including a trigonal Sapphire wafer containing a (0001) C-plane and having front and rear sides. The Sapphire wafer is substantially transparent to light in the visible and infrared spectra, and also provides insulation with respect to electromagnetic radio frequency noise. A layer of crystalline Si material having a cubic diamond structure aligned with the cubic <111> direction on the (0001) C-plane and strained as rhombohedron to thereby enable continuous integration of a selected (SiGe) device onto the rear side of the Sapphire wafer. The double sided hybrid crystal structure further includes an integrated III-Nitride crystalline layer on the front side of the Sapphire wafer that enables continuous integration of a selected III-Nitride device on the front side of the Sapphire wafer.

An InGaN/GaN multiple quantum well blue light detector- includes: a Si substrate, an AlN/AlGaN/GaN buffer layer, a u-GaN/AlN/u-GaN/SiN.sub.x/u-GaN buffer layer, an n-GaN buffer layer, an InGaN/GaN superlattice layer and an InGaN/GaN multiple quantum well layer in sequence from bottom to top. The multiple quantum well layer has a groove and a mesa, the mesa and the groove of the multiple quantum well layer are provided with a Si.sub.3N.sub.4 passivation layer. The passivation layer in the groove is provided with a first metal layer electrode with a semicircular cross section, and the passivation layer on the mesa is provided with second metal layer electrode.

A light detection device includes a substrate, a buffer layer disposed on the substrate, a first band gap change layer disposed on a portion of the buffer layer, a light absorption layer disposed on the first band gap change layer, a Schottky layer disposed on a portion of the light absorption layer, and a first electrode layer disposed on a portion of the Schottky layer.

Photovoltaic devices including direct gap III-V absorber materials and operatively associated back structures enhance efficiency by enabling photon recycling. The back structures of the photovoltaic devices include wide bandgap III-V layers, highly doped (In)GaAs layers, patterned oxide layers and metal reflectors that directly contact the highly doped (In)GaAs layers through vias formed in the back structures. Localized ohmic contacts are formed in the back structures of the devices.

A superlattice and method for forming that superlattice are disclosed. In particular, an engineered layered single crystal structure forming a superlattice is disclosed. The superlattice provides p-type or n-type conductivity, and comprises alternating host layers and impurity layers, wherein: the host layers consist essentially of a semiconductor material; and the impurity layers consist of a donor or acceptor material.

A semiconductor wafer comprising a substrate; a first AlGaN layer on the substrate; a second AlGaN layer on the first AlGaN layer; a GaN layer on the second AlGaN layer; and a plurality of crystalline GaN islands between the first and second AlGaN layers.

This work provides a new approach for epitaxial liftoff. Instead of using a sacrificial layer that is selectively etched chemically, the sacrificial layer selectively absorbs light that is not absorbed by other parts of the structure. Under sufficiently intense illumination with such light, the sacrificial layer is mechanically weakened, melted and/or destroyed, thereby enabling epitaxial liftoff. The perimeter of the semiconductor region to be released is defined (partially or completely) by lateral patterning, and the part to be released is also adhered to a support member prior to laser irradiation. The end result is a semiconductor region removed from its substrate and adhered to the support member.

Embodiments described herein relate to a dual-band photodetector. The dual-band photodetector includes a barrier layer (10) disposed between two infrared absorption layers (8, 12) wherein the barrier layer (10) is lattice matched to at least one of the infrared absorption layers (8, 12). Furthermore, one infrared absorption layer includes dilute nitride to adjust the band gap to a desired cut-off wavelength while maintaining valence-band alignment with the barrier layer. Embodiments also relate to a system and processes for producing the photodetector fabricated from semiconductor materials.

In an embodiment, a method includes treating an edge region of a wafer including a substrate having an upper surface and one or more epitaxial Group III nitride layers arranged on the upper surface of the substrate, so as to remove material including at least one Group III element from the edge region.