An optoelectronic device includes an etched body comprising a buried metal contact layer on a top surface of a semiconductor structure, which comprises one or more semiconductor layers. The buried metal contact layer includes an arrangement of holes therein. A plurality of nanopillar structures protrude from the top surface of the semiconductor structure and pass through the arrangement of holes. Each nanopillar structure is surrounded at a base thereof by a portion of the buried metal contact layer. When the etched body is exposed to incident radiation having a wavelength in the range from about 300 nm to about 10 microns, at least about 50% of the incident radiation is transmitted through the etched body at a peak transmission wavelength .sub.max.

The invention relates to quantum dot and photodetector technology, and more particularly, to quantum dot infrared photodetectors (QDIPs) and focal plane array. The invention further relates to devices and methods for the enhancement of the photocurrent of quantum dot infrared photodetectors in focal plane arrays.

The invention relates to a method for fabricating a semiconductor device. The method includes steps of providing a cavity structure, the cavity structure including a seed area including a seed material. The method further includes growing, within the cavity structure, a first embedding layer in a first growth direction from a seed surface of the seed material. The method includes further steps of removing the seed material, growing, in a second growth direction, from a seed surface of the first embedding layer, a quantum dot structure and growing, within the cavity structure, on a surface of the quantum dot structure, a second embedding layer in the second growth direction. The second growth direction is different from the first growth direction. The invention further relates to devices obtainable by such a method.

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.

This invention includes quantum dot channel (QDC) Si FETs, which detect infrared radiation to serve as photodetectors. GeOx-cladded Ge quantum dots form the quantum dot channel. An assembly of cladded quantum dots, such as Ge and Si, with thin barrier layers (GeOx and SiOx) form a quantum dot superlattice (QDSL). A QDSL exhibits narrow energy widths of sub-bands (or mini-energy bands) with sub-bands separation ranging 0.2-0.5 eV. The energy separation depends on the barrier thickness (0.5-1 nm) and diameter of quantum dots (3-5 nm). Drain current magnitude in a QDSL layer or quantum dot channel depends on density of electrons in the QD inversion channel, which in turn depends on number of sub-bands participating in the conduction for a given drain voltage VD and gate voltage VG. Infrared photons with energy corresponding to the intra sub-band separation are absorbed as electrons in a lower sub-band make transition to the upper sub-band.

An infrared sensor is provided, which includes a light absorption layer that absorbs an infrared ray. The light absorption layer includes quantum dots. The quantum dots include 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. Moreover, the light absorption layer includes a quantum dot layer divided into at least two regions, including the quantum dots and having mutually different absorption edge wavelengths, out of a wavelength region from a near-infrared region to a far-infrared region.

A quantum dot includes a core and a shell. The core includes a compound semiconductor and has a polyhedral shape. The polyhedral shape includes multiple surfaces and a vertex at which multiple edges between the surfaces adjacent to each other converge. The shell is provided at the surfaces and has a thickness at the part around the vertex in a vertical direction with respect to any one of the surfaces. The thickness is greater than a thickness at a part other than the part around the vertex in the same direction.

Plasmonic substrates are provided which may be used in a variety of optoelectronic devices, e.g., biosensors and photodetectors. The plasmonic substrate may comprise a layer of graphene and a plurality of discrete, individual transition metal chalcogenide nanodomes distributed on a surface of the layer of graphene, each nanodome surrounded by bare graphene. Methods for making and using the plasmonic substrates are also provided.

Techniques for realizing compound semiconductor (CS) optoelectronic devices on silicon (Si) substrates are disclosed. The integration platform is based on heteroepitaxy of CS materials and device structures on Si by direct heteroepitaxy on planar Si substrates or by selective area heteroepitaxy on dielectric patterned Si substrates. Following deposition of the CS device structures, device fabrication steps can be carried out using Si complimentary metal-oxide semiconductor (CMOS) fabrication techniques to enable large-volume manufacturing. The integration platform can enable manufacturing of optoelectronic module devices including photodetector arrays for image sensors and vertical cavity surface emitting laser arrays. Such module devices can be used in various applications including light detection and ranging (LIDAR) systems for automotive and robotic vehicles as well as mobile devices such as smart phones and tablets, and for other perception applications such as industrial vision, artificial intelligence (AI), augmented reality (AR) and virtual reality (VR).

A photodetector device to act as an artificial photonic synapse includes a substrate and a perovskite quantum dot-multiwall carbon nanotube (PQD-MWCNT) hybrid material. The PQD-MWCNT hybrid material channel is disposed on the substrate between a first electrode and a second electrode and forms a PQD-MWCNT channel. The PDQs comprise a methylammonium lead bromide material. A method of operating the photodetector device as an artificial photonic synapse includes applying a presynaptic signal as stimuli as one or more light pulses on the PQD-MWCNT channel between the first electrode and the second electrode. A current across the PQD-MWCNT channel is measured to represent a postsynaptic signal.