According to the present disclosure, techniques related to manufacturing and applications of power photodiode structures and devices based on group-III metal nitride and gallium-based substrates are provided. More specifically, embodiments of the disclosure include techniques for fabricating photodiode devices comprising one or more of GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, structures and devices. Such structures or devices can be used for a variety of applications including optoelectronic devices, photodiodes, power-over-fiber receivers, and others.

The present disclosure provides an integrated infrared circular polarization detector with a high extinction ratio and a design method thereof. The detector structurally includes a metal reflective layer, a bottom electrode layer, a quantum well layer, a top electrode layer, and a two-dimensional chiral metamaterial layer. Under circularly polarized light with the selected handedness, surface plasmon polariton waves are generated at the interface between the two-dimensional chiral metamaterial layer and the semiconductor, and has a main electric field component aligned with the absorption direction of the quantum wells, thereby enhancing the absorption of the quantum wells. Under circularly polarized light with the opposite handedness, since most of the optical power is reflected, surface plasmon polariton waves cannot be effectively excited, and the absorption of the quantum wells is extremely low, thus realizing the capability of infrared circular polarization detection with a high extinction ratio.

Photovoltaic devices, and methods of fabricating photovoltaic devices. The photovoltaic devices may include a first electrode, at least one quantum dot layer, at least one semiconductor layer, and a second electrode. The first electrode may include a layer including Cr and one or more silver contacts.

An ICIP comprises: a number N.sub.s of IC stages, wherein N.sub.s is configured to achieve a fundamental limit of the detectivity D.sub.peak* the ICIP within a range, and wherein each of the IC stages comprises: a hole barrier; an absorber coupled to the hole barrier and comprising a thickness d, wherein d is configured to achieve D.sub.peak* within the range; and an electron barrier coupled to the absorber. A method of manufacturing an ICIP comprises: determining a number N.sub.s of IC stages of the ICIP, wherein N.sub.s is configured to achieve a peak detectivity D.sub.peak* of the ICIP within a range; determining a thickness d of an absorber, wherein d is configured to achieve D.sub.peak* within the range; obtaining a substrate; forming an electron barrier on the substrate, the absorber having d on the electron barrier, and a hole barrier on the absorber; and repeating the forming N.sub.s times.

An electric field drives nanocrystals dispersed in solvents to assemble into ordered three-dimensional superlattices. A first electrode and a second electrode 214 are in the vessel. The electrodes face each other. A fluid containing charged nanocrystals fills the vessel between the electrodes. The electrodes are connected to a voltage supply which produces an electrical field between the electrodes. The nanocrystals will migrate toward one of the electrodes and accumulate on the electrode producing ordered nanocrystal accumulation that will provide a superlattice thin film, isolated superlattice islands, or coalesced superlattice islands.

A photodetector designing method includes, according to various requirements required by an application equipped with a photodetector including a photoelectric conversion layer having a superlattice structure mostly composed of amorphous selenium, a step of determining a form of the photodetector; a step of determining a type of a substrate suitable for a wavelength to be detected by the photoelectric conversion layer among the requirements, a step of calculating a multiplication factor M representing an amplification gain generated in a process of tunneling in the superlattice structure, and a step of determining, as a layer thickness of the photoelectric conversion layer, a thickness obtained by multiplying a thickness per one layer of the superlattice structure by the number of layers N.sub.SL of the superlattice structure on the assumption that the multiplication factor M is approximate to the number of layers N.sub.SL.

A composition of matter comprising: a plurality of group III-V nanowires or nanopyramids epitaxially grown on a polycrystalline or single-crystalline graphene layer, said graphene layer being directly supported on a crystalline substrate such as a group III-V semiconductor, sapphire, SiC or diamond substrate, wherein the epitaxy, crystal orientation and facet orientations of said nanowires or nanopyramids are directed by the crystalline substrate.

A photodetection element that includes: a substrate with a high infrared transmittance in a desired wavelength region; an electron barrier layer of a type-I superlattice structure, the electron barrier layer being formed above the substrate and lattice-matched to the substrate; and a light-receiving layer of a type-II superlattice structure, formed in contact with the electron barrier layer.

An improved heterostructure for an optoelectronic device is provided. The heterostructure includes an active region, an electron blocking layer, and a p-type contact layer. The heterostructure can include a p-type interlayer located between the electron blocking layer and the p-type contact layer. In an embodiment, the electron blocking layer can have a region of graded transition. The p-type interlayer can also include a region of graded transition.

A monolithically integrated, tunable infrared pixel comprises a combined broadband detector and graphene-enabled tunable metasurface filter that operate as a single solid-state device with no moving parts. Functionally, tunability results from the plasmonic properties of graphene that are acutely dependent upon the carrier concentration within the infrared. Voltage induced changes in graphene's carrier concentration can be leveraged to change the metasurface filter's transmission thereby altering the “colors” of light reaching the broadband detector and hence its spectral responsivity. The invention enables spectrally agile infrared detection with independent pixel-to-pixel spectral tunability.