Various particular embodiments include a method for forming a photodetector, including: forming a structure including a barrier layer disposed between a layer of doped silicon (Si) and a layer of germanium (Ge), the barrier layer including a crystallization window; and annealing the structure to convert, via the crystallization window, the Ge to a first composition of silicon germanium (SiGe) and the doped Si to a second composition of SiGe.

Bias-switchable dual-band infrared detectors and methods of manufacturing such detectors are provided. The infrared detectors are based on a back-to-back heterojunction diode design, where the detector structure consists of, sequentially, a top contact layer, a unipolar hole barrier layer, an absorber layer, a unipolar electron barrier, a second absorber, a second unipolar hole barrier, and a bottom contact layer. In addition, by substantially reducing the width of one of the absorber layers, a single-band infrared detector can also be formed.

A layered OP material is provided that comprises an OPGaAs template, and a layer of GaP on the OPGaAs template. The OPGaAs template comprises a patterned layer of GaAs having alternating features of inverted crystallographic polarity of GaAs. The patterned layer of GaAs comprises a first feature comprising a first crystallographic polarity form of GaAs having a first dimension, and a second feature comprising a second crystallographic polarity form of GaAs having a second dimension. The layer of GaP on the patterned layer of GaAs comprises alternating regions of inverted crystallographic polarity that generally correspond to their underlying first and second features of the patterned layer of GaAs. Additionally, each of the alternating regions of inverted crystallographic polarity of GaP are present at about 100 micron thickness or more. A method of forming the OPGaP is also provided.

A photo-sensing unit including a first electrode, a first insulation layer, a photo-sensing structure and a second electrode is provided. The first insulation layer covers the first electrode and has an opening exposing the first electrode. The photo-sensing structure is located on the first electrode and disposed in the opening of the first insulation layer. The photo-sensing structure includes a first photo-sensing layer and a second photo-sensing layer stacked with each other. A material of the first photo-sensing layer is Si.sub.xGe.sub.yO.sub.z. A material of the second photo-sensing layer is Si.sub.vO.sub.w. The second electrode covers the photo-sensing structure. A photo-sensing apparatus including the photo-sensing unit and a fabricating method of a photo-sensing unit are also provided.

A particle detector includes a support member. A front electrode layer is disposed over the support member. A semiconductor heterojunction is disposed over the front electrode layer. The semiconductor heterojunction has at least a polycrystalline n-type layer and at least a polycrystalline p-type layer. A back electrode layer is disposed over the semiconductor heterojunction. The back electrode includes at least one removed portion that separates a first portion of the back electrode layer from a second portion of the back electrode layer. The particle detector also includes a first body of electrically insulating material which separates a first portion of the semiconductor heterojunction from a second portion of the semiconductor heterojunction. The first body of electrically insulating material also separates a first portion of the front electrode layer from a second portion of the front electrode layer.

A sensor includes an InGaAs photodetector configured to convert received infrared radiation into electrical signals. A notch filter is operatively connected to the InGaAs photodetector to block detection of wavelengths within at least one predetermined band. An imaging camera system includes an InGaAs photodetector configured to convert received infrared radiation into electrical signals, the InGaAs photodetector including an array of photodetector pixels each configured to convert infrared radiation into electrical signals for imaging. At least one optical element is optically coupled to the InGaAs photodetector to focus an image on the array. A notch filter is operatively connected to the InGaAs photodetector to block detection of wavelengths within at least one predetermined band. A ROIC is operatively connected to the array to condition electrical signals from the array for imaging.

A photodetector includes an insulating layer on a substrate, a first graphene layer on the insulating layer, a 2-dimensional (2D) material layer on the first graphene layer, a second graphene layer on the 2D material layer, a first electrode on the first graphene layer, and a second electrode on the second graphene layer. The 2D material layer includes a barrier layer and a light absorption layer. The barrier layer has a larger bandgap than the light absorption layer.

Light-receiving elements and the like that can more simply absorb and transmit light are provided.

A Light-receiving element includes a lens unit condensing incident light to emit the light from an emission surface, an absorption layer arranged on the emission surface of the lens unit to absorb part of the condensed light and transmit the remaining condensed light, and a detection layer placed on the absorption layer to detect intensity of light emitted from the lens unit, on the basis of intensity of light absorbed by the absorption layer.

There is provided a photodetector, comprising a semiconductor heterostructure having in sequence: a first collection layer having substantially uniform doping of a first doping type; a radiation-absorbing layer having substantially uniform doping of the first doping type and having a band gap less than or equal to that of the first collection layer; and a barrier layer having a band gap greater than that of the radiation-absorbing layer, the top of the valence band of the barrier layer being substantially equal in energy to that of the radiation-absorbing layer where the first doping type is n-type or the bottom of the conduction band of the barrier layer being substantially equal in energy to that of the radiation-absorbing layer where the first doping type is p-type; wherein a first portion of the barrier layer is of the first doping type and a second portion of the barrier layer is of a second doping type, the first portion of the barrier layer being adjacent to the radiation-absorbing layer, forming a heterojunction within the barrier layer which gives rise to a depletion region within each portion of the barrier layer.

A semiconductor light receiving device includes a substrate, a semiconductor fine line waveguide provided on the substrate, and a light receiving circuit that is provided on the substrate and that absorbs light propagating through the semiconductor fine line waveguide. The light receiving circuit includes a p type first semiconductor layer, a number of second semiconductor mesa structures provided on the p type first semiconductor layer in such a manner that an n type second semiconductor layer is provided on top of an i type second semiconductor layer, a p side electrode connected to the p type first semiconductor layer in a location between the second semiconductor mesa structures, and an n side electrode connected to the n type second semiconductor layer. The refractive index and the optical absorption coefficient of the second semiconductor layers are greater than the refractive index and the optical absorption coefficient of the first semiconductor layer.