A three-terminal avalanche photodiode provides a first controllable voltage drop across a light absorbing region and a second, independently controllable, voltage drop across a photocurrent amplifying region. The compositions of the absorbing region and the amplifying region may be optimized independently of each other. In the amplifying region, p-doped and n-doped structures are offset from each other both horizontally and vertically. Directly applying a voltage across a controlled region of the photocurrent path increases avalanche gain by shaping the electric field to overlap the photocurrent density. The resulting high-gain, low-bias avalanche photodiodes may be fabricated in integrated optical circuits using commercial CMOS processes, operated by power supplies common to mature computer architecture, and used for optical interconnects, light sensing, and other applications.

A photoelectronic device includes a substrate; a first electrode and a second electrode disposed on the substrate and spaced apart from each other in a first direction; and a transition metal dichalcogenide thin film including at least one first region and at least one second region. Each first region includes M+N transition metal dichalcogenide molecular layers and extends along the first direction. Each second region includes N transition metal dichalcogenide molecular layers extending from lower N transition metal dichalcogenide molecular layers of the first region. Each second region extends along the first direction and is adjacent to each first region. Both end regions in the first direction among the first and the second regions are electrically connected to the first electrode and the second electrode, respectively.

Techniques to use energy band gap engineering (or band offset engineering) to produce a photodetector semiconductor assembly that can be tuned to absorb light in one or more wavelengths. For example, the assembly can be tuned to receive infrared (IR) and/or ultraviolet (UV) light. The photodetector assembly can operate as a photodiode, a phototransistor, or can include both a photodiode and a phototransistor.

An inexpensive IR photodetector assembly that can provide high performance in SWIR applications, such as LIDAR. The photodetector assembly can operate as a photodiode, a phototransistor, or can include both a photodiode and a phototransistor. The hybrid photodetector can be composed of one or more absorber layer materials from a first semiconductor family, e.g., p-type InGaAs, laying on one or more wide-band gap semiconductor transducer layer materials from a second semiconductor family, e.g., aluminum gallium nitride (AlGaN) and gallium nitride (GaN), or AlGaN/n-GaN. As such, the absorber layer material and the wide band gap materials can be from two different semiconductor families, making the IR photodetector a hybrid of semiconductor families. After shining IR light onto the absorber layer material, the photo-generated electron-hole pairs can be collected as photocurrent in the photo-voltaic mode.

Silicon-based or other electronic circuitry is dissolved or otherwise disabled by reactive materials within a semiconductor chip should the chip or a device containing the chip be subjected to tampering. Triggering circuits containing normally-OFF heterojunction field-effect photo-transistors are configured to cause reactions of the reactive materials within the chips upon exposure to light. The normally-OFF heterojunction field-effect photo-transistors can be fabricated during back-end-of-line processing through the use of polysilicon channel material, amorphous hydrogenated silicon gate contacts, hydrogenated crystalline silicon source/drain contacts, or other materials that allow processing at low temperatures.

A Dual-wavelength hybrid (DWH) device includes an n-type ohmic contact layer, cathode and anode terminal electrodes, first and second injector terminal electrodes, p-type and n-type modulation doped QW structures, and first through sixth ion implant regions. The first injector terminal electrode is formed on the third ion implant region that contacts the p-type modulation doped QW structure and the second injector terminal electrode is formed on the fourth ion implant region that contacts the n-type modulation doped QW structure. The DWH device operates in at least one of a vertical cavity mode and a whispering gallery mode. In the vertical cavity mode, the DWH device converts an in-plane optical mode signal to a vertical optical mode signal, whereas in the whispering gallery mode the DWH device converts a vertical optical mode signal to an in-plane optical mode signal.

A photoelectric conversion device may include a substrate, a photoactive layer disposed on the substrate, and a first electrode and a second electrode respectively connected to corresponding edges of the photoactive layer. The photoactive layer may include a first oxide semiconductor layer on the substrate, and a plurality of quantum dot layers and a plurality of second oxide semiconductor layers that are alternately formed on the first oxide semiconductor layer.

A photosensitive field-effect transistor configured to provide an electrical response when illuminated by electromagnetic radiation incident on the transistor. The photosensitive field-effect transistor comprises a layer of two-dimensional material which forms a horizontal transistor channel configured to transport current, and a horizontal semiconducting layer in contact with the transistor channel. The semiconducting layer comprises two or more assemblies of semiconducting material. If the two-dimensional material in the transistor channel has a high work function, the assemblies of semiconducting material are vertically stacked on the transistor channel in order of decreasing work function. If the two-dimensional material in the transistor channel has a low work function, the assemblies of semiconducting material are vertically stacked on the transistor channel in order of increasing work function. The semiconducting materials may, for example, comprise semiconductor nanocrystals, quantum dots or thin-film semiconducting layers.

Germanium-based sensors are disclosed herein. An exemplary germanium-based sensor includes a germanium photodiode and a junction field effect transistor (JFET) formed from a germanium layer disposed on and/or in a silicon substrate. A doped silicon layer, which can be formed by in-situ doping epitaxially grown silicon, is disposed between the germanium layer and the silicon substrate. In embodiments where the germanium layer is on the silicon substrate, the doped silicon layer is disposed between the germanium layer and an oxide layer. The JFET has a doped polysilicon gate, and in some embodiments, a gate diffusion region is disposed in the germanium layer under the doped polysilicon gate. In some embodiments, a pinned photodiode passivation layer is disposed in the germanium layer. In some embodiments, a pair of doped regions in the germanium layer is configured as an e-lens of the germanium-based sensor.

In an embodiment, a photodetector is provided that provides a sensitizing medium adapted to receive electromagnetic radiation creating a junction with a transport channel, wherein the transport channel is adapted to exhibit a change in conductivity in response to reception of electromagnetic radiation by the sensitizing medium.