Disclosed is a photo detector. The photo detector includes: a conductive substrate; an insulating layer formed on the conductive substrate; a single-layer graphene formed at one part of an upper end of the insulating layer and formed in one layer; a multi-layer graphene formed at the other part of the upper end of the insulating layer and formed in multiple layers; a first electrode formed at an end of the single-layer graphene; and a second electrode formed at an end of the multi-layer graphene.

Embodiments of the present disclosure are directed to infrared detector devices incorporating a tunneling structure. In one embodiment, an infrared detector device includes a first contact layer, an absorber layer adjacent to the first contact layer, and a tunneling structure including a barrier layer adjacent to the absorber layer and a second contact layer adjacent to the barrier layer. The barrier layer has a tailored valence band offset such that a valence band offset of the barrier layer at the interface between the absorber layer and the barrier layer is substantially aligned with the valence band offset of the absorber layer, and the valence band offset of the barrier layer at the interface between the barrier layer and the second contact layer is above a conduction band offset of the second contact layer.

The semiconductor device comprises a semiconductor substrate (2), a transition layer (5) in or on the semiconductor substrate, the transition layer allowing propagation of incident radiation (7) according to a refractive index, and a photonic component (4) facing the transition layer. A surface (6) of the transition layer is structured such that the effective refractive index is gradually changed through the transition layer with changing distance from the photonic component.

A method for fabricating a semiconductor proximity sensor includes providing a flat leadframe with a first and a second surface. The second surface is solderable. The leadframe includes a first and a second pad, a plurality of leads, and fingers framing the first pad. The fingers are spaced from the first pad by a gap which is filled with a clear molding compound. A light-emitting diode (LED) chip is assembled on the first pad and encapsulated by a first volume of the clear compound. The first volume outlined as a first lens. A sensor chip is assembled on the second pad and encapsulated by a second volume of the clear compound. The second volume outlined as a second lens. Opaque molding compound fills the space between the first and second volumes of clear compound and forms walls rising from the frame of fingers to create an enclosed cavity for the LED. The pads, leads, and fingers connected to a board using a layer of solder for attaching the proximity sensor.

A superlattice cell that includes Group IV elements is repeated multiple times so as to form the superlattice. Each superlattice cell has multiple ordered atomic planes that are parallel to one another. At least two of the atomic planes in the superlattice cell have different chemical compositions. One or more of the atomic planes in the superlattice cell one or more components selected from the group consisting of carbon, tin, and lead. These superlattices make a variety of applications including, but not limited to, transistors, light sensors, and light sources.

An object is to provide an infrared sensor with a quantum dot optimized. The present invention provides an infrared sensor (1) including a light absorption layer (5) that absorbs an infrared ray, wherein the light absorption layer includes a plurality of spherical quantum dots (21). Alternatively, the present invention provides an infrared sensor including a light absorption layer that absorbs an infrared ray, wherein the light absorption layer includes a plurality of quantum dots and the quantum dot includes at least one kind of PbS, PbSe, CdHgTe, Ag.sub.2S, Ag.sub.2Se, Ag.sub.2Te, AgInSe.sub.2, AgInTe.sub.2, CuInSe.sub.2, CuInTe.sub.2, and InAs.

An object is to provide an infrared sensor with a quantum dot optimized. The present invention provides an infrared sensor (1) including a light absorption layer (5) that absorbs an infrared ray, wherein the light absorption layer includes a plurality of spherical quantum dots (21). Alternatively, the present invention provides an infrared sensor including a light absorption layer that absorbs an infrared ray, wherein the light absorption layer includes a plurality of quantum dots and the quantum dot includes at least one kind of PbS, PbSe, CdHgTe, Ag.sub.2S, Ag.sub.2Se, Ag.sub.2Te, AgInSe.sub.2, AgInTe.sub.2, CuInSe.sub.2, CuInTe.sub.2, and InAs.

Methods, apparatus and systems are described that relate to uncooled long-wave infrared (LWIR) photodetectors capable of operating at room temperature and having a simple structure that can be manufactured at low cost. One example LWIR photodetector includes a layer of amorphous silicon (a-Si) disposed on a silicon substrate and a layer of amorphous germanium (a-Ge) disposed on the a-Si layer, wherein the a-Ge layer is operable to absorb infrared light and provide photoconductive gain, and the a-Si layer is operable to produce carrier multiplication via cycling excitation process.

A differential amplifier includes an unmatched pair, including first quantum dots and second quantum dots, and a matched pair, including first and second phototransistors. The unmatched pair has a difference between a first spectrum absorbed by the first quantum dots and a second spectrum absorbed by the second quantum dots. Each of the first and second phototransistors includes a channel. The first quantum dots absorb the first spectrum from incident electromagnetic radiation and gate a first current through the channel of the first phototransistor, and the second quantum dots absorb the second spectrum from the incident electromagnetic radiation and gate a second current through the channel of the second phototransistor. The first and second phototransistors are coupled together for generating a differential output from the first and second currents, the differential output corresponding to the difference between the first and second spectrums within the incident electromagnetic radiation.

The present disclosure describes an embodiment of a thin film transistor based light sensor circuit. The thin film transistor based light sensor circuit includes two thin film transistors, in which a channel region of one of the thin film transistors includes a light sensing area and a channel region of the other thin film transistor has a capping material disposed thereon. The thin film transistor based light sensor circuit further includes a comparator device electrically coupled to the two thin film transistors and configured to detect a current difference between the thin film transistors in response to the thin film transistor with the channel region having the light sensing area being exposed to light.