A bio-inspired imaging device mimicking visual adaptation of human vision provides a large dynamic range in imaging an image. The device employs a neuromorphic vision sensor realized with phototransistors each being a field-effect transistor, a channel layer of which is an atomically-thin layer of two-dimensional semiconductor material. The channel layer is intentionally formed with defects trap states for trapping a portion of charge carriers generated by a light beam incident on the phototransistor such that intensity information of the light beam is memorized. A gate-source voltage directs the defects trap states to de-trap the trapped portion of charge carriers or to further trap an additional portion of charge carriers, allowing the phototransistor to exhibit a time-dependent excitation or inhibition effect on drain current to thereby enable the imaging sensor to mimic scotopic or photopic adaptation in imaging the image.

A method includes providing a semiconductor substrate having a front side surface and a back side surface opposite to the front side surface. A photosensitive region of the semiconductor substrate is etched to form a recess. A semiconductor material is deposited on the semiconductor substrate to form a radiation sensing member filling the recess. The semiconductor material has an optical band gap energy smaller than 1.77 eV. A device layer is formed over the front side surface of the semiconductor substrate and the radiation sensing member. A trench isolation is formed in an isolation region of the semiconductor substrate and extending from the back side surface of the semiconductor substrate.

An electrical device includes a substrate with a compressive layer, a neutral stress buffer layer and a tensile stress compensation layer. The stress buffer layer and the stress compensation layer may each be formed with aluminum nitride using different processing parameters to provide a different intrinsic stress value for each layer. The aluminum nitride tensile layer is configured to counteract stresses from the compressive layer in the device to thereby control an amount of substrate bow in the device. This is useful for protecting fragile materials in the device, such as mercury cadmium telluride. The aluminum nitride stress compensation layer also can compensate for forces, such as due to CTE mismatches, to protect the fragile layer. The device may include temperature-sensitive materials, and the aluminum nitride stress compensation layer or stress buffer layer may be formed at a temperature below the thermal degradation temperature of the temperature-sensitive material.

A photovoltaic device (100) can include an absorber layer (160). The absorber layer (160) can be doped p-type with a Group V dopant and can have a carrier concentration of the Group V dopant greater than 4×10.sup.15 cm.sup.−3. The absorber layer (160) can include oxygen in a central region of the absorber layer (160). The absorber layer (160) can include an alkali metal in the central region of the absorber layer (160). Methods for carrier activation can include exposing an absorber layer (160) to an annealing compound in a reducing environment (220). The annealing compound (224) can include cadmium chloride and an alkali metal chloride.

Embodiments of a photovoltaic device are provided herein. The photovoltaic device can include a layer stack and an absorber layer disposed on the layer stack. The absorber layer can include a first region and a second region. Each of the first region of the absorber layer and the second region of the absorber layer can include a compound comprising cadmium, selenium, and tellurium. An atomic concentration of selenium can vary across the absorber layer. The first region of the absorber layer can have a thickness between 100 nanometers to 3000 nanometers. The second region of the absorber layer can have a thickness between 100 nanometers to 3000 nanometers. A ratio of an average atomic concentration of selenium in the first region of the absorber layer to an average atomic concentration of selenium in the second region of the absorber layer can be greater than 10.

In an example, a wireless gamma and or hard X-ray radiation detector includes a bulk semiconductor crystal, electrical contacts, a bias circuit, and a terahertz (THz) electromagnetic (EM) wave receiver. The bulk semiconductor crystal and includes indium antimonide (InSb), cadmium telluride (CdTe), or cadmium zinc telluride (CdZnTe). The electrical contacts are coupled to two facets of the bulk semiconductor crystal. The bias circuit is electrically coupled to the bulk semiconductor crystal through the electrical contacts. The THz EM wave receiver is positioned to detect THz radiation emitted by the bulk semiconductor crystal.

The present disclosure provides a photodiode based on a stannous selenide sulfide nanosheet/GaAs heterojunction and a preparation method and use thereof. The photodiode comprises a structure of the stannous selenide sulfide nanosheet/GaAs heterojunction, forming Au electrodes through thermal vapor deposition on the stannous selenide sulfide nanosheet and GaAs, respectively, and conducting an annealing treatment in a protective gas at a temperature in a range of 150-250° C. The heterojunction is formed by transferring the stannous selenide sulfide nanosheet to a GaAs window, and the GaAs window is obtained by depositing a medium layer film on GaAs and etching the medium layer through lithography and an etchant.

A radiation detection probe and a manufacturing method therefor, and a radiation detection chip. The method comprises: simulating each of a plurality of cadmium zinc telluride crystals having different three-dimensional sizes; obtaining the radiation response characteristics of each cadmium zinc telluride crystal; according to the radiation response characteristics, selecting a specific cadmium zinc telluride crystal from the plurality of cadmium zinc telluride crystals, wherein the specific cadmium zinc telluride crystal is a cadmium zinc telluride crystal having optimal performance indexes corresponding to the radiation response characteristics in the plurality of cadmium zinc telluride crystals; and configuring a first electrode and a second electrode for the specific cadmium zinc telluride crystal so as to constitute the radiation detection probe.

The present invention proposes a method to form a CdSeTe thin film with a defined amount of selenium and with a high quality. The method comprises the steps of providing a base substrate and of depositing a partial CdSeTe layer on a first portion of the base substrate. The step of depositing a partial CdSeTe layer is performed at least twice, wherein a predetermined time period without deposition of a partial CdSeTe layer on the first portion of the base substrate is provided between two subsequent steps of depositing a partial CdSeTe layer. The temperature of the base substrate and the CdSeTe layer already deposited on the first portion of the base substrate is controlled during the predetermined time period such that re-evaporation of Cd and/or Te from the CdSeTe layer already deposited takes place.

According to the embodiments provided herein, a photovoltaic device can include an absorber layer. The absorber layer can be doped p-type with a Group V dopant and can have a carrier concentration of the Group V dopant greater than 4×10.sup.15 cm.sup.−3. The absorber layer can include oxygen in a central region of the absorber layer. The absorber layer can include an alkali metal in the central region of the absorber layer. Methods for carrier activation can include exposing an absorber layer to an annealing compound in a reducing environment. The annealing compound can include cadmium chloride and an alkali metal chloride.