A detector for detecting single photons of infrared radiation. In one embodiment a waveguide configured to transmit infrared radiation is arranged to be adjacent a graphene sheet and configured so that evanescent waves from the waveguide overlap the graphene sheet. In some embodiments the waveguide is omitted and infrared light propagating in free space illuminates the graphene sheet directly. A photon absorbed by the graphene sheet from the evanescent waves heats the graphene sheet. The graphene sheet is coupled to the weak link of a Josephson junction, and a constant bias current is driven through the Josephson junction, so that an increase in the temperature of the graphene sheet results in a decrease in the critical current of the Josephson junction and a voltage pulse in the voltage across the Josephson junction. The voltage pulse is detected by the pulse detector.

A photodetector including a substrate, a light absorption layer arranged over the substrate, the light absorption layer including a stack including a semiconductor layer that absorbs light of a wavelength having an electric field vector parallel to a normal direction of a substrate surface, a lower contact layer arranged on a first side of the light absorption layer, a lower electrode contacting with the lower contact layer, an upper contact layer arranged on a second side of the light absorption layer, and an upper electrode contacting with the upper contact layer. An uneven structure including polarization-selective shapes of projections or depressions on the second side of the upper contact layer is provided, the shapes of projections or depressions each having a size of a wavelength or less of incident light in the semiconductor layer and half the wavelength or greater and being periodically arranged in at least one direction.

Techniques for processing materials for manufacture of gallium-containing nitride substrates are disclosed. More specifically, techniques for fabricating and reusing large area substrates using a combination of processing techniques are disclosed. The methods can be applied to fabricating substrates of GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, and others. Such substrates can be used for a variety of applications including optoelectronic devices, lasers, light emitting diodes, solar cells, photo electrochemical water splitting and hydrogen generation, photo detectors, integrated circuits, transistors, and others.

Radiation detecting-structures and fabrications methods thereof are presented. The methods include, for instance: providing a substrate, the substrate including at least one trench extending into the substrate from an upper surface thereof; and epitaxially forming a radiation-responsive semiconductor material layer from one or more sidewalls of the at least one trench of the substrate, the radiation-responsive semiconductor material layer responding to incident radiation by generating charge carriers therein. In one embodiment, the sidewalls of the at least one trench of the substrate include a (111) surface of the substrate, which facilitates epitaxially forming the radiation-responsive semiconductor material layer. In another embodiment, the radiation-responsive semiconductor material layer includes hexagonal boron nitride, and the epitaxially forming includes providing the hexagonal boron nitride with an a-axis aligned parallel to the sidewalls of the trench.

A photovoltaic device, particularly a solar cell, comprises an interface between a layer of Group III-V material and a layer of Group IV material with a thin silicon diffusion barrier provided at or near the interface. The silicon barrier controls the diffusion of Group V atoms into the Group IV material, which is doped n-type thereby. The n-type doped region can provide the p-n junction of a solar cell in the Group IV material with superior solar cell properties. It can also provide a tunnel diode in contact with a p-type region of the III-V material, which tunnel diode is also useful in solar cells.

An LED device capable of emitting electromagnetic radiation ranging from about 200 nm to 365 nm, the device. The device includes a substrate member, the substrate member being selected from sapphire, silicon, quartz, gallium nitride, gallium aluminum nitride, or others. The device has an active region overlying the substrate region, the active region comprising a light emitting spatial region comprising a p-n junction and characterized by a current crowding feature of electrical current provided in the active region. The light emitting spatial region is characterized by about 1 to 10 microns. The device includes an optical structure spatially disposed separate and apart the light emitting spatial region and is configured to facilitate light extraction from the active region.

The method for growing an elongate element (5), notably a wire of nanowire or microwire type, includes forming a nucleation surface (3) having at least one germination site adopting the form of a germination hollow (7) and delimited at least partly by a mask (2), the at least one germination hollow (7) being situated at a distance from the mask (2), performing nucleation of a seed (4) intended to participate in the growth of the elongate element (5) on the at least one germination hollow (7), and growing the elongate element (5) from the seed (4).

The present invention provides materials, structures, and methods for III-nitride-based devices, including epitaxial and non-epitaxial structures useful for III-nitride devices including light emitting devices, laser diodes, transistors, detectors, sensors, and the like. In some embodiments, the present invention provides metallo-semiconductor and/or metallo-dielectric devices, structures, materials and methods of forming metallo-semiconductor and/or metallo-dielectric material structures for use in semiconductor devices, and more particularly for use in III-nitride based semiconductor devices. In some embodiments, the present invention includes materials, structures, and methods for improving the crystal quality of epitaxial materials grown on non-native substrates. In some embodiments, the present invention provides materials, structures, devices, and methods for acoustic wave devices and technology, including epitaxial and non-epitaxial piezoelectric materials and structures useful for acoustic wave devices. In some embodiments, the present invention provides metal-base transistor devices, structures, materials and methods of forming metal-base transistor material structures for use in semiconductor devices.

A method of producing an optoelectronic semiconductor chip includes providing a growth substrate and a semiconductor layer sequence grown on the growth substrate with a main extension plane including a p-conductive layer, an active zone and an n-conductive layer, removing the semiconductor layer sequence in regions to form at least one aperture extending through the p-conductive layer and the active zone into the n-conductive layer of the semiconductor layer sequence, depositing a protective layer on a side of the semiconductor layer sequence facing away from the growth substrate, depositing an aluminum layer containing aluminum across the entire surface on a side of the semiconductor layer sequence facing away from the growth substrate, removing the growth substrate, and forming a mesa by removing the semiconductor layer sequence at the regions of the protective layer, wherein the protective layer is subsequently freely externally accessible at least in places.

Embodiments relate to use of a particle accelerator beam to form thin films of material from a bulk substrate are described. In particular embodiments, a bulk substrate having a top surface is exposed to a beam of accelerated particles. In certain embodiments, this bulk substrate may comprise GaN; in other embodiments this bulk substrate may comprise (111) single crystal silicon. Then, a thin film or wafer of material is separated from the bulk substrate by performing a controlled cleaving process along a cleave region formed by particles implanted from the beam. In certain embodiments this separated material is incorporated directly into an optoelectronic device, for example a GaN film cleaved from GaN bulk material. In some embodiments, this separated material may be employed as a template for further growth of semiconductor materials (e.g. GaN) that are useful for optoelectronic devices.