The photodetector device generally has a semiconductor substrate; a plurality of nanowires extending from the semiconductor substrate, the nanowires having a first section of a first semiconductor material extending from the semiconductor substrate, a tunnel junction extending from the first section, and a second section of a second semiconductor material extending from the tunnel junction, the first semiconductor material having a first bandgap energy different from a second bandgap energy of the second semiconductor material; an electrode longitudinally spaced apart from the second sections, and forming a gap therebetween; an electrolyte solution within the gap and surrounding the nanowires; and a current detector having a first terminal electrically connected to the semiconductor substrate and a second terminal electrically connected to the electrode.

A semiconductor device includes a semiconductor layer, which is disposed on the surface of a substrate and causing an oxidation reaction and a reduction reaction when irradiated with light, an oxidation catalyst layer, which is disposed on part of the surface of the semiconductor layer, forms along with the semiconductor layer a Schottky junction, and oxidizes an oxidation target substance, a reduction catalyst layer, which is disposed on part of the surface of the semiconductor layer where the oxidation catalyst layer is not disposed so as to be separated from the oxidation catalyst layer, forms along with the semiconductor layer an ohmic junction, and reduces a reduction target substance, and an insulation layer, which is disposed on the entirety of the surface of the semiconductor layer where none of the oxidation catalyst layer and the reduction catalyst layer is disposed so as to be in contact with the oxidation catalyst layer and the reduction catalyst layer.

Betavoltaic battery devices and methods of making are presented. In embodiments, an electrically inactive betavoltaic battery device comprises: a p-type semiconductor layer including at least one stable isotope that transforms into a beta emitter upon irradiation with thermal neutrons; and an n-type semiconductor beta-absorber layer configured to absorb beta particles; wherein the p-type semiconductor layer and the n-type semiconductor layer form a p-n diode, and wherein the electrically inactive betavoltaic battery device is configured to be transformed into an electrically active betavoltaic battery upon irradiation with thermal neutrons. The electrically inactive betavoltaic battery device may be transported to an irradiation facility, where it is irradiated with thermal neutrons to convert the inactive betavoltaic batter device to an active betavoltaic battery device.

The invention relates to a semiconductor device, e.g. for the emission or absorption of light, preferably in the deep ultraviolet (DUV) range. The device, e.g. a resonant cavity light emitting diode (RCLED) or a laser diode, is formed from: a substrate layer (302), preferably comprising a distributed Bragg reflector (DBR); a graphitic layer (304); and at least one semiconductor structure (310), preferably a wire or a pyramid, grown on the graphitic layer, with or without the use of a mask layer (306). The semiconductor structure is constructed from at least one III-V semiconductor n-type doped region (316) and a hexagonal boron-nitride (hBN) region (312), preferably being p-type doped hBN.

Devices, systems and methods for operating and using an optically quenchable carbon-doped gallium nitride photoconductive semiconductor switch (PCSS) are described. An example method includes illuminating a carbon-doped gallium nitride material of the photoconductive semiconductor switch with a first laser light within a first range of wavelengths to trigger the photoconductive semiconductor switch to a conductive state, turning off or blocking the first laser light, and illuminating the carbon-doped gallium nitride material with a second laser light within a second range of wavelengths to trigger the photoconductive semiconductor switch to an insulating state. In this example, the first range of wavelengths comprises an ultraviolet (UV) or a blue wavelength range, the second range of wavelengths comprises an infrared (IR) or a red wavelength range, and switching from the conductive state to the insulating state occurs within a sub-nanosecond range.

A device including an activated p-type layer comprising a III-Nitride based Mg-doped layer grown by vapor phase deposition or a growth method different from MBE. The p-type layer is activated through a sidewall of the p-type layer after the removal of defects from the sidewall thereby increasing a hole concentration in the p-type layer. In one or more examples, the device includes an active region between a first n-type layer and the p-type layer; a second n-type layer on the p-type layer; and a tunnel junction between the second n-type layer and the p-type layer, and the activated p-type layer has a hole concentration characterized by a current density of at least 100 Amps per centimeter square flowing between the first n-type layer and the second n-type layer in response to a voltage of 4 volts or less applied across the first n-type layer and the second n-type layer.

The present invention relates to a GaN-based radiation detector capable of detecting radiation such as X-rays. The GaN-based radiation detector includes: an n-doped GaN layer having an electron mobility of 700 cm.sup.2/(V.Math.s) or more and a thickness of 300 m or more and doped with an n-type doping concentration of 310.sup.16/cm.sup.3 or less; a p-doped GaN layer formed on one surface of the n-doped GaN layer and having a thickness of 3 m or less and doped with a p-type doping concentration of 510.sup.18/cm.sup.3 or more; a first metal contact formed on the other surface of the n-doped GaN layer; and a second metal contact formed on one surface of the p-doped GaN layer.