A multicolor imaging device capable of imaging two or more wavelengths with a single pixel comprises an avalanche photodiode having a material composition such that only one carrier causes substantially all of the impact ionization that occurs within the photodiode. The photodiode is arranged such that, when reverse-biased, the photodiode's gain varies with the photon energy of incident light. The photodiode, preferably a PIN avalanche photodiode or a separate absorber-multiplier photodiode, produces an output signal which can include at least two components produced in response to two different wavelengths of incident light. Circuitry receiving the output signal would typically include a means of extracting each of the components from the output signal.

A method of fabricating a four-junction solar cell includes: forming a first epitaxial structure comprising first and second subcells and a cover layer over a first substrate through a forward epitaxial growth, and forming a second epitaxial structure comprising third and fourth subcells over the second substrate; forming a groove and a metal bonding layer; forming a groove on the cover layer surface of the first epitaxial structure and the substrate back surface of the second epitaxial structure, and depositing a metal bonding layer in the groove; and bonding the first epitaxial structure and the second epitaxial structure; bonding the cover layer surface of the first epitaxial structure and the substrate back surface of the second epitaxial structure, ensuring that the metal bonding layers are aligned to each other to realize dual bonding between the metal bonding layers and between the semiconductors through high temperature and high pressure treatment.

A tiled array of hybrid assemblies and a method of forming such an array enables the assemblies to be placed close together. Each assembly comprises first and second dies, with the second die mounted on and interconnected with the first die. Each vertical edge of a second die which is to be located adjacent to a vertical edge of another second die in the tiled array is etched such that the etched edge is aligned with a vertical edge of the first die. Indium bumps are deposited on a baseplate where the hybrid assemblies are to be mounted, and the assemblies are mounted onto respective indium bumps using a hybridizing machine, enabling the assemblies to be placed close together, preferably 10 m. The first and second dies may be, for example. a detector and a readout IC, or an array of LEDs and a read-in IC.

Disclosed herein are compositions and methods for making polycrystalline thin films having very large grains sizes and exhibiting improved properties over existing thin films.

According to the embodiments provided herein, a method for forming a photovoltaic device can include depositing a plurality of semiconductor layers. The plurality of semiconductor layers can include a doped layer that is doped with a group V dopant. The doped layer can include cadmium selenide or cadmium telluride. The method can include annealing the plurality of semiconductor layers to form an absorber layer.

A tiled array of hybrid assemblies and a method of forming such an array enables the assemblies to be placed close together. Each assembly comprises first and second dies, with the second die mounted on and interconnected with the first die. Each vertical edge of a second die which is to be located adjacent to a vertical edge of another second die in the tiled array is etched such that the etched edge is aligned with a vertical edge of the first die. Indium bumps are deposited on a baseplate where the hybrid assemblies are to be mounted, and the assemblies are mounted onto respective indium bumps using a hybridizing machine, enabling the assemblies to be placed close together, preferably 10 m. The first and second dies may be, for example. a detector and a readout IC, or an array of LEDs and a read-in IC.

An ultraviolet photodetector for a sensor device includes a film deposited on a substrate. The film includes a compositionally graded magnesium-zinc oxide having a ratio of magnesium-to-zinc that decreases between a portion of the film adjacent to the substrate and a portion of the film opposite the substrate for shifting the peak absorption of the film toward the visible wavelengths of the electromagnetic spectrum.

A method for fabricating an optically transparent conductor including depositing a plurality of metal nanowires on a substrate, annealing or illuminating the plurality of metal nanowires to thermally or optically fuse nanowire junctions between metal nanowires to form a metal nanowire network, disposing a graphene layer over the metal nanowire network to form a nanohybrid layer comprising the graphene layer and the metal nanowire network, depositing a dielectric passivation layer over the nanohybrid layer, patterning the dielectric passivation layer using lithography, printing, or any other method of patterning to define an area for the optically transparent conductor, and etching the patterned dielectric passivation layer to define the optically transparent conductor.

A radiation detector is provided that includes a photodiode having a radiation absorber with a graded multilayer structure. Each layer of the absorber is formed from a semiconductor material, such as HgCdTe. A first of the layers is formed to have a first predetermined wavelength cutoff. A second of the layers is disposed over the first layer and beneath the first surface of the absorber through which radiation is received. The second layer has a graded composition structure of the semiconductor material such that the wavelength cutoff of the second layer varies from a second predetermined wavelength cutoff to the first predetermined wavelength cutoff such that the second layer has a progressively smaller bandgap than the first bandgap of the first layer. The graded multilayer radiation absorber structure enables carriers to flow toward a conductor that is used for measuring the radiation being sensed by the radiation absorber.

A photovoltaic device includes a substrate, a first electrode formed on the substrate and a p-type absorber layer including a chalcogenide compound. An n-type layer includes a zinc oxysulfide material having a sulfur content adjusted to match a feature of the absorber layer. A transparent contact is formed on the n-type layer.