A short-wave infra-red, SWIR, radiation detection device comprises: a first metallic layer providing a first set of connections from a readout circuit to respective cells of a matrix, the metallic layer reflecting SWIR wavelength radiation. Each matrix cell comprises at least one stack of layers including: a first layer of doped semiconductor material formed on the first metallic layer; an at least partially microcrystalline semiconductor layer formed over the first doped layer; a second layer of semiconductor material formed on the microcrystalline semiconductor layer; at least one microcrystalline semiconductor layer; and in some embodiments a second metallic layer interfacing the microcrystalline semiconductor layer(s), the interface being responsive to incident SWIR radiation to generate carriers within the stack. The stack has a thickness

[00001]$T=\frac{}{2N}$

between reflective surfaces of the first and second metallic layers.

An infrared detector and a method for forming it are provided. The detector includes absorber, barrier, and contact regions. The absorber region includes a first semiconductor material, with a first lattice constant, that produces charge carriers in response to infrared light. The barrier region is disposed on the absorber region and comprises a superlatice that includes (i) first barrier region layers comprising the first semiconductor material, and (ii) second barrier region layers comprising a second semiconductor material, different from, but lattice matched to, the first semiconductor material. The first and second barrier region layers are alternatingly arranged. The contact region is disposed on the barrier region and comprises a superlattice that includes (i) first contact region layers comprising the first semiconductor material, and (ii) second contact region layers comprising the second semiconductor material layer. The first and second contact region layers are alternatingly arranged.

An infrared detector and a method for forming it are provided. The detector includes absorber, barrier, and contact regions. The absorber region includes a first semiconductor material, with a first lattice constant, that produces charge carriers in response to infrared light. The barrier region is disposed on the absorber region and comprises a superlatice that includes (i) first barrier region layers comprising the first semiconductor material, and (ii) second barrier region layers comprising a second semiconductor material, different from, but lattice matched to, the first semiconductor material. The first and second barrier region layers are alternatingly arranged. The contact region is disposed on the barrier region and comprises a superlattice that includes (i) first contact region layers comprising the first semiconductor material, and (ii) second contact region layers comprising the second semiconductor material layer. The first and second contact region layers are alternatingly arranged.

Processes and devices for continuous compositional grading in photodetectors and electro-absorption modulators (EAM) are provided. An example photodetector includes a multi-layered structure comprising a collector region, an absorber region, a grading layer, and a peripheral layer, all aligned along a detection axis. The grading layer, positioned adjacent to the absorber region, includes multiple sub-layers that define a continuous compositional grading to facilitate smooth carrier transport and reduce recombination. Similarly, an example electro-absorption modulator (EAM) device includes a waveguide mesa formed on a semiconductor substrate, comprising a multi-quantum well (MQW) core layer, upper and lower near-core cladding layers, and upper and lower central cladding layers. The EAM device features both upper and lower grading layers, each positioned between the near-core cladding layers and the adjacent central cladding layers. These grading layers include multiple sub-layers that define a continuous compositional grading, facilitating smooth transitions between the MQW core and surrounding cladding layers.

A contact to a semiconductor heterostructure is described. In one embodiment, there is an n-type semiconductor contact layer. A light generating structure formed over the n-type semiconductor contact layer has a set of quantum wells and barriers configured to emit or absorb target radiation. An ultraviolet transparent semiconductor layer having a non-uniform thickness is formed over the light generating structure. A p-type contact semiconductor layer having a non-uniform thickness is formed over the ultraviolet transparent semiconductor layer.

The present invention relates to a semiconductor photosensitive unit and a semiconductor photosensitive unit array thereof, including a floating gate transistor, a gating MOS transistor and a photodiode that are disposed on a semiconductor substrate. An anode or a cathode of the photodiode is connected to a floating gate of the floating gate transistor through the gating MOS transistor, and the corresponding cathode or anode of the photodiode is connected to a drain of the floating gate transistor or connected to an external electrode. After the gating MOS transistor is switched on, the floating gate is charged or discharged through the photodiode; and after the gating MOS transistor is switched off, charges are stored in the floating gate of the floating gate transistor. Advantages like a small unit area, low surface noise, long charge storage time of the floating gate, and large dynamic range of an operating voltage are achieved.

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.

The present invention discloses an Er doped Ga.sub.2O.sub.3 film, together with its preparation method and the application in the field of luminescence. The preparation method contains steps of: (1) the films are deposited by means of Radio-Frequency magnetron sputtering onto the heated substrates after the pre-sputtering for at least 5 minutes, selecting Er doped Ga.sub.2O.sub.3 target or Er and Ga.sub.2O.sub.3 targets, with the ambient of Ar and O.sub.2; (2) the films as prepared in step (1) are thermally treated at the temperature higher than 300 C. in the ambient of O.sub.2 or N.sub.2, in order to optically activate Er.sup.3+ and crystalize Ga.sub.2O.sub.3 hosts meanwhile, followed by natural cooling, obtaining the Er doped Ga.sub.2O.sub.3 films as described. The preparation technology of the present invention is simple, with a good process compatibility. It is believed that the present invention will be widely used in the field of silicon-based integrated light sources, semiconductor luminescence, optical communication, with broad application prospects.

The present invention discloses an Er doped Ga.sub.2O.sub.3 film, together with its preparation method and the application in the field of luminescence. The preparation method contains steps of: (1) the films are deposited by means of Radio-Frequency magnetron sputtering onto the heated substrates after the pre-sputtering for at least 5 minutes, selecting Er doped Ga.sub.2O.sub.3 target or Er and Ga.sub.2O.sub.3 targets, with the ambient of Ar and O.sub.2; (2) the films as prepared in step (1) are thermally treated at the temperature higher than 300 C. in the ambient of O.sub.2 or N.sub.2, in order to optically activate Er.sup.3+ and crystalize Ga.sub.2O.sub.3 hosts meanwhile, followed by natural cooling, obtaining the Er doped Ga.sub.2O.sub.3 films as described. The preparation technology of the present invention is simple, with a good process compatibility. It is believed that the present invention will be widely used in the field of silicon-based integrated light sources, semiconductor luminescence, optical communication, with broad application prospects.