A light sensing circuit for solving the problem of low reliability in illumination detection includes a photo transistor having a gate, a drain and a source; a first transistor electrically connecting between the gate and source of the photo transistor; a first capacitor electrically connecting between the gate and the drain of the photo transistor; a second transistor electrically connecting with the drain of the photo transistor, the first capacitor, and a data signal; a second capacitor electrically connecting between the source of the photo transistor and a ground contact; a third transistor electrically connecting with the photo transistor, the first transistor, and the second capacitor; and a switch adapted to alternatively connect the third transistor with a buffer or a zero signal. A control method of the above light sensing circuit is also disclosed. Therefore, the above identified problem can be surely solved.

The disclosure provides a photo-detection device for use in long-wave infrared detection and a method of fabrication. The device comprises a GaSb substrate, a photo absorbing layer comprising InAs/InAsSb superlattice type-II, a barrier layer comprising AlAsSb, and a contact layer comprising InAs/InAsSb superlattice type-II. The barrier layer is configured to allow minority carrier holes current flow while blocking majority carrier electrons current flow between the photo-absorbing and contact layers. The disclosure further provides a method of producing the photo-detector using photolithography which includes selective etching of the contact layer that stops on the top of the barrier so no etching is made to the barrier layer so the barrier may operate as a passivator too. The disclosure presents an x-ray and photoluminescence results for InAs/InAsSb superlattice type-II material. Also present a measurement of a single element, Long-Wave photo-detector, showing very low dark current and very high Quantum efficiency, as predicted.

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.

A light receiving sensor (1) includes: a photodiode (PD) which generates a photocurrent (Ipd) upon receipt of light; a transistor (Tr11) through which the photocurrent (Ipd) flows; a transistor (Tr12) which forms, together with the transistor (Tr11), a first current mirror circuit (CM1); a transistor (Tr9) whose channel type is different from that of the transistor (Tr11), and a resistor (R10) which converts, to a voltage, a current flowing through the transistors (Tr11 and Tr12). The first current mirror circuit (CM1) amplifies the photocurrent (Ipd), the transistor (Tr11) has a source connected with a gate of a MOS transistor (Tr9), and the MOS transistor (Tr9) has a threshold voltage that is set to be equal to or above a threshold voltage of the transistor (Tr11). This decreases a capacity of the photodiode (PD) and therefore allows the light receiving sensor (1) to operate at a high speed while the photodiode (PD) is biased.

There is described a photodetector comprising a semiconductor material having at least a region substantially depleted of free moving carriers, the photodetector comprising: a substrate of one of n-type and p-type; at least one charge collector along a surface of the substrate and having a doping-type opposite from the substrate; a substrate contact along the surface of the substrate spaced apart from the at least one charge collector to allow current to flow between the at least one charge collector and the substrate contact; and at least one non-conductive electrode positioned along the surface of the substrate in an alternating sequence with the at least one charge collector, and separated from the substrate by an insulator, and adapted to apply an electric potential to the substrate and cause charge carriers generated therein by application of a light source to advance towards the at least one charge collector due to the effects of an electric field, such that the at least one charge collector can measure carrier concentration within the substrate.

An LED device capable of emitting electromagnetic radiation ranging from about 200 nm to 365 nm, the device. The device includes a substrate member, the substrate member being selected from sapphire, silicon, quartz, gallium nitride, gallium aluminum nitride, or others. The device has an active region overlying the substrate region, the active region comprising a light emitting spatial region comprising a p-n junction and characterized by a current crowding feature of electrical current provided in the active region. The light emitting spatial region is characterized by about 1 to 10 microns. The device includes an optical structure spatially disposed separate and apart the light emitting spatial region and is configured to facilitate light extraction from the active region.

The present invention discloses a photo-detector comprising: an n-type photon absorbing layer of a first energy bandgap; a middle barrier layer, an intermediate layer is a semiconductor structure; and a contact layer of a third energy bandgap, wherein the layer materials are selected such that the first energy bandgap of the photon absorbing layer is narrower than that of said middle barrier layer; wherein the material composition and thickness of said intermediate layer are selected such that the valence band of the intermediate layer lies above the valence band in the barrier layer to create an efficient trapping and transfer of minority carriers from the barrier layer to the contact layer such that a tunnel current through the barrier layer from the contact layer to the photon absorbing layer is less than a dark current in the photo-detector and the dark current from the photon-absorbing layer to said middle barrier layer is essentially diffusion limited and is due to the unimpeded flow of minority carriers, thus reducing generation-recombination (GR) noise of the photo-detector. The principles of the present invention also apply to inverted polarity structures of the form pBp in which all the doping polarities and band alignments described above are reversed.

A graphene device and a method of operating the same are provided. The graphene device includes: an active layer including a plurality of meta atoms spaced apart from each other, each of the meta atoms having a radial shape, and a graphene layer that contacts each of the plurality of meta atoms; and a dielectric layer covering the active layer.

Described embodiments include optical connections for electronic-photonic devices, such as optical waveguides and photonic detectors for receiving optical waves from the optical waveguides and directing the optical waves to a common point. Methods of fabricating such connections are also described.

A semiconductor device is disclosed, which includes: at least one a device layer being a crystallized layer for example including: a superlattice layer and/or a layer of group III-V semiconductor materials; and a passivation structure comprising one or more layers wherein at least one layer of the passivation structure is a passivation layer grown in-situ in a crystallized form on top of the device layer, and at least one of the one or more layers of the passivation structure includes material having a high density of surface states which forces surface pinning of an equilibrium Fermi level within a certain band gap of the device layer, away from its conduction and valence bands.