Photovoltaic devices and methods for fabricating a photovoltaic devices. The method includes applying a coating layer that surrounds each of a plurality of silicon particles. The method also includes implanting the plurality of silicon particles into a substrate layer such that an exposed portion of each of the plurality of silicon particles extends away from a surface of the substrate layer. The method further includes removing a portion of the coating layer that is positioned around the exposed portion of each of the plurality of silicon particles. The method also includes placing an insulator layer on the surface of the substrate layer. The method further includes placing a selective carrier transport layer on the exposed portion of each of the plurality of silicon particles.

An optical device useful for spatial light modulation. The device comprises: a semiconductor layer having a first surface and a second surface, the semiconductor having an electric field-dependent resonance wavelength; a first electrode electrically connected to the semiconductor layer; a first insulating layer adjacent to the first surface of the semiconductor layer, and a second insulating layer adjacent to the second surface of the semiconducting layer, the first and the second insulating layers each being optically transparent at the resonance wavelength; a first group of at least one gate electrodes disposed adjacent to the first insulating layer, and a second group of at least one gate electrodes disposed adjacent to the second insulating layer, each gate electrode being at least 80% optically transparent at the resonance wavelength; wherein the first and the second groups of gate electrodes, taken together, form at least two regions in the semiconductor layer, an electrostatic field in each of the at least two regions being independently controllable by application of voltage to the first and the second groups of gate electrodes, the at least two regions abutting each other along at least one boundary.

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.

Optically sensitive devices include a device comprising a first contact and a second contact, each having a work function, and an optically sensitive material between the first contact and the second contact. The optically sensitive material comprises a p-type semiconductor, and the optically sensitive material has a work function. Circuitry applies a bias voltage between the first contact and the second contact. The optically sensitive material has an electron lifetime that is greater than the electron transit time from the first contact to the second contact when the bias is applied between the first contact and the second contact. The first contact provides injection of electrons and blocking the extraction of holes. The interface between the first contact and the optically sensitive material provides a surface recombination velocity less than 1 cm/s.

Provided are a nanostructure and an optical device including the nanostructure. The nanostructure is formed on a two-dimensional material layer such as graphene and includes nanopatterns having different shapes. The nanopatterns may include a first nanopattern and a second nanopattern and may be spherical; cube-shaped; or poly-pyramid-shaped, including a triangular pyramid shape; or polygonal pillar-shaped.

The disclosure is directed at a method and apparatus for producing a detector element. The detector element includes first and second electrodes located on opposites sides of a semiconductor layer. The first and second electrodes are staggered with respect to each other in a plane perpendicular to the semiconductor layer.

The present disclosure relates to a terahertz wave generation apparatus capable of wavefront control. A terahertz wave generating apparatus according to an exemplary embodiment comprises a photoconductive substrate; and a plurality of terahertz wave generating unit elements arranged in a two-dimensional array on the photoconductive substrate. Also, the terahertz wave generating unit elements comprise a plurality of first electrodes arranged in the two-dimensional array on the photoconductive substrate and respectively connected to a plurality of first electrode pads, and at least one second electrode formed on the photoconductive substrate so as to face the first electrodes.

An imaging device with excellent imaging performance is provided. An imaging device that easily performs imaging under a low illuminance condition is provided. A low power consumption imaging device is provided. An imaging device with small variations in characteristics between its pixels is provided. A highly integrated imaging device is provided. A photoelectric conversion element includes a first electrode, and a first layer, a second layer, and a third layer. The first layer is provided between the first electrode and the third layer. The second layer is provided between the first layer and the third layer. The first layer contains selenium. The second layer contains a metal oxide. The third layer contains a metal oxide and also contains at least one of a rare gas atom, phosphorus, and boron. The selenium may be crystalline selenium. The second layer may be a layer of an InGaZn oxide including c-axis-aligned crystals.

A photoconductive device that generates or detects terahertz radiation includes a semiconductor layer; a structure portion; and an electrode. The semiconductor layer has a thickness no less than a first propagation distance and no greater than a second propagation distance, the first propagation distance being a distance that the surface plasmon wave propagates through the semiconductor layer in a perpendicular direction of an interface between the semiconductor layer and the structure portion until an electric field intensity of the surface plasmon wave becomes 1/e times the electric field intensity of the surface plasmon wave at the interface, the second propagation distance being a distance that a terahertz wave having an optical phonon absorption frequency of the semiconductor layer propagates through the semiconductor layer in the perpendicular direction until an electric field intensity of the terahertz wave becomes 1/e.sup.2 times the electric field intensity of the terahertz wave at the interface.