Photo-detectors disclosed include at least one of a thin film or a heterostructure of photo-sensitive material and a pair of Ohmic contacts coupled to the at least one of the thin film or the heterostructure. The at least one of the thin film or the heterostructure is configured to be under a strain gradient to induce shift current flow within the material to perform photo-detection in a frequency range that includes a mid-infrared frequency range. The photo-detectors provided for can include a variety of configurations, such as a lateral configuration or a vertical configuration, and can operate in self-powered and negative illumination regimes. Associated methods are also provided, which can include inducing a strain gradient and performing photo-detection in a frequency range that includes a mid-infrared frequency range.

A compact collision detector can be configured for low power operation to facilitate collision avoidance. In one embodiment, a nanoscale collision detector can be based on a photodetector, stacked on top of a non-volatile and programmable memory architecture that imitates the escape response of LGMD neuron at a frugal energy expenditure of few nanojoules (nJ) and at the same time can offer orders of magnitude benefit in device footprint (e.g. by having a relatively small size). Embodiments of the collision detector can be utilized in smart, low-cost, task-specific, energy efficient and miniaturized collision detection systems configured for collision avoidance.

A compact collision detector can be configured for low power operation to facilitate collision avoidance. In one embodiment, a nanoscale collision detector can be based on a photodetector, stacked on top of a non-volatile and programmable memory architecture that imitates the escape response of LGMD neuron at a frugal energy expenditure of few nanojoules (nJ) and at the same time can offer orders of magnitude benefit in device footprint (e.g. by having a relatively small size). Embodiments of the collision detector can be utilized in smart, low-cost, task-specific, energy efficient and miniaturized collision detection systems configured for collision avoidance.

Provided are a light-receiving element which has more capability of detecting wavelengths than that of existing silicon light-receiving elements and a unit pixel of an image sensor by using it. The light-receiving element includes: a light-receiving unit which is floated or connected to external voltage and absorbs light; an oxide film which is formed to come in contact with a side of the light-receiving unit; a source and a drain which stand off the light-receiving unit with the oxide film in between and face each other; a channel which is formed between the source and the drain and forms an electric current between the source and the drain; and a wavelength expanding layer which is formed in at least one among the light-receiving unit, the oxide film and the channel and forms a plurality of local energy levels by using strained silicon.

As the optoelectronic synaptic device according to a preferred embodiment includes a photoactive layer in which a heterojunction is formed as inorganic quantum dots that accept a near-infrared light signal directly contacts a transition metal dichalcogenide as a two-dimensional semiconductor material that exhibits synaptic characteristics, there is an effect of making a synaptic response to an optical signal in the near-infrared wavelength range. Therefore, as a function of simulating the human visual-brain function, which shows the neuromorphic characteristics by the photo response (visual response) of the infrared wavelength, together with light detection characteristics sensitively and rapidly responding to an infrared wavelength signal as well as a visible light signal, can be implemented in a single device for the sake of accurate recognition of objects, it can be easily applied in the autonomous driving mobility field.

The disclosure provides a group-III nitride device. The group-III nitride device includes a heterojunction epitaxial wafer and at least one island-shaped electrode. The at least one island-shaped electrode of the group-III nitride device is disposed on the heterojunction epitaxial wafer. Each of the at least one island-shaped electrode includes an interconnection metal layer and at least one island-shaped structural layer. The island-shaped structural layer is covered by the interconnection metal layer and connected to the interconnection metal layer.

An image sensor device includes nanostructures for improving light absorption efficiency. The image sensor device includes a substrate doped with a first dopant of a first conductivity type, and a light absorption region over the substrate. The light absorption region is doped with a second dopant of a second conductivity type. The second conductivity type is different from the first conductivity type. The nanostructures overlap the light absorption region. One of the nanostructures has a bottom surface at a different level than a top surface of the light absorption region.

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 pixel structure comprising: a diode body comprising: a base portion protruding from a substrate and a main portion on top of the base portion, wherein a footprint of the base portion is smaller than a footprint of the main portion, and wherein the main portion comprises first and second oppositely doped regions formed in a top portion of the main portion, wherein the first and second doped regions are formed in a central part and along a periphery, respectively, of the footprint of the main portion; a gate arranged to circumferentially surround the diode body, comprising a first gate portion surrounding the main portion and a second gate portion protruding inwardly from the first gate portion to undercut the main portion and surround the base portion; a gate dielectric layer arranged to separate the gate and the diode body; and first and second diode terminals, and a gate terminal.

An optoelectronic device comprises a gapped graphene system (GGS) a top gate electrode, a bottom gate electrode and a controller configured for applying a voltage bias between the gate electrodes to effect a bandgap in the GGS, wherein the bandgap is selected to allow the GGS to receive or emit light having a terahertz frequency.