A light detection element includes a semiconductor substrate, a light absorbing layer of a first conductivity type formed on the semiconductor substrate, a cap layer of a first conductivity type formed on the light absorbing layer, and a semiconductor region of a second conductivity type formed within the cap layer and forming a pn junction with the cap layer. A depletion layer formed around the semiconductor region does not reach the light absorbing layer in a case where a reverse bias is not applied to the pn junction, and exceeds a position amounting to 50% of a thickness of the light absorbing layer from the cap layer side in a case where a reverse bias of 20 V is applied to the pn junction.

An integrated circuit structure comprising a substrate having an upper surface; a gallium nitride layer disposed on the upper surface of the substrate; and a photoconductive semiconductor switch laterally disposed alongside a transistor on the gallium nitride layer integrated into the integrated circuit structure wherein a regrown gallium nitride material is disposed on the photoconductive semiconductor switch and operatively coupled with the wafer.

A semiconductor light receiving element of back-illuminated type comprises a light absorbing portion formed in the vicinity of the main surface of the semiconductor substrate transparent to the incident light, and a first convex lens portion larger than the light absorbing portion and having a radius of curvature R1 formed on a back surface of the semiconductor substrate, a second convex lens portion smaller than the light absorbing portion and having a radius of curvature R2 smaller than the radius of curvature R1; the second convex lens portion formed on the first convex lens portion and having a focal point between the second convex lens portion and the light absorbing portion; light incident on the second convex lens portion is diffused from the focal point toward the light absorbing portion.

A light detecting device includes a light absorbing layer configured to absorb light in a wavelength range from visible light to short-wave infrared (SWIR); a first semiconductor layer provided on a first surface of the light absorbing layer; an anti-reflective layer provided on the first semiconductor layer and comprising a material having etch selectivity with respect to the first semiconductor layer; and a second semiconductor layer provided on a second surface of the light absorbing layer. The first semiconductor layer has a thickness less than 500 nm so as to be configured to allow light to transmit therethrough in the wavelength range from visible light to SWIR.

A photo detector includes a superlattice with an undoped first semiconductor layer including undoped intrinsic semiconductor material, a doped second semiconductor layer having a first conductivity type on the first semiconductor layer, an undoped third semiconductor layer including undoped intrinsic semiconductor material on the second semiconductor layer, and a fourth semiconductor layer having a second opposite conductivity type on the third semiconductor layer, along with a first contact having the first conductivity type in the first, second, third, and fourth semiconductor layers, and a second contact having the second conductivity type and spaced apart from the first contact in the first, second, third, and fourth semiconductor layers. An optical shield on a second shielded portion of a top surface of the fourth semiconductor layer establishes electron and hole lakes. A packaging structure includes an opening that allows light to enter an exposed first portion of the top surface of the fourth semiconductor layer.

A photo-detecting device includes a substrate, a first semiconductor layer, a light-absorbing layer, a second semiconductor layer, a semiconductor contact layer, an insulating layer, and an electrode structure. The second semiconductor layer includes a first region and a second region. The semiconductor contact layer is on the first region. The insulating layer covers the semiconductor contact layer, the first region, and the second region. The electrode structure covers the semiconductor contact layer, the insulating layer, the first region, and the second region.

A photodetection element that includes: a substrate with a high infrared transmittance in a desired wavelength region; an electron barrier layer of a type-I superlattice structure, the electron barrier layer being formed above the substrate and lattice-matched to the substrate; and a light-receiving layer of a type-II superlattice structure, formed in contact with the electron barrier layer.

Systems and methods for thermal radiation detection utilizing a thermal radiation detection system are provided. The thermal radiation detection system includes one or more mercury-cadmium-telluride (HgCdTe)-based photodiode infrared detectors or Indium Arsenide (InAr)-based photodiode infrared detectors and a temperature sensing circuit. The temperature sensing circuit is configured to generate signals correlated to the temperatures of one or more of the plurality of infrared sensor elements. The thermal radiation detection system also includes a signal processing circuit.

A stacked III-V semiconductor photonic device having a second metallic terminal contact layer at least formed in regions, a highly doped first semiconductor contact region of a first conductivity type, a very low doped absorption region of the first or second conductivity type having a layer thickness of 20 μm-2000 μm, a first metallic terminal contact layer, wherein the first semiconductor contact region extends into the absorption region in a trough shape, the second metallic terminal contact layer is integrally bonded to the first semiconductor contact region and the first metallic terminal contact layer is arranged below the absorption region. In addition, the stacked III-V semiconductor photonic device has a doped III-V semiconductor passivation layer of the first or second conductivity type, wherein the III-V semiconductor passivation layer is arranged at a first distance of at least 10 μm to the first semiconductor contact region.

A light receiving device includes a substrate, a first contact layer disposed on a surface of the substrate, a light receiving layer disposed on the first contact layer, an intermediate layer disposed on the light receiving layer, a wide-gap layer having a pn junction disposed on the intermediate layer, a second contact layer disposed on the wide-gap layer, and a groove formed for pixel isolation by removing the second contact layer and part of the wide-gap layer, wherein the intermediate layer has a wider band gap than the light receiving layer, and wherein the wide-gap layer has a wider band gap than the intermediate layer.