An infrared detector and a method for forming it are provided. The detector includes absorber, barrier, and contact regions. The absorber region includes a first semiconductor material, with a first lattice constant, that produces charge carriers in response to infrared light. The barrier region is disposed on the absorber region and comprises a superlatice that includes (i) first barrier region layers comprising the first semiconductor material, and (ii) second barrier region layers comprising a second semiconductor material, different from, but lattice matched to, the first semiconductor material. The first and second barrier region layers are alternatingly arranged. The contact region is disposed on the barrier region and comprises a superlattice that includes (i) first contact region layers comprising the first semiconductor material, and (ii) second contact region layers comprising the second semiconductor material layer. The first and second contact region layers are alternatingly arranged.

Barrier infrared detectors configured to operate in the long-wave (LW) infrared regime are provided. The barrier infrared detector systems may be configured as pin, pbp, barrier and double heterostructrure infrared detectors incorporating optimized p-doped absorbers capable of taking advantage of high mobility (electron) minority carriers. The absorber may be a p-doped Ga-free InAs/InAsSb material. The p-doping may be accomplished by optimizing the Be doping levels used in the absorber material. The barrier infrared detectors may incorporate individual superlattice layers having narrower periodicity and optimization of Sb composition to achieve cutoff wavelengths of ˜10 μm.

The present invention relates to a focal plane array having a substrate wafer; an n-type indium arsenide layer disposed atop the substrate wafer; a barrier layer disposed atop the substrate wafer; and a doped n-type layer disposed atop the barrier layer. The present invention further relates to a focal plane array, having a substrate wafer; an n-type indium arsenide layer disposed atop the substrate wafer; and a p-type indium arsenide layer positioned at a first surface of the n-type indium arsenide layer opposite an interface surface of the n-type indium arsenide and the substrate wafer.

Provided is a high-quality substrate including a silicon layer, a multilayer buffer layer on the silicon layer, and an indium phosphide (InP) layer on the multilayer buffer layer, wherein a crystal growth direction of the silicon layer is a direction inclined by 1° to 10° with respect to a vertical direction, and wherein the multilayer buffer layer includes a buffer layer in which a crystal growth direction is inclined with respect to the vertical direction.

A phototransistor includes an emitter, a collector, and a base between the emitter and the collector. The base has a thickness greater than 500 nanometers and the base absorbs photons passing through the collector to the base.

An exemplary quantum dot device can be provided, which can include, for example, at least three conductive layers and at least two insulating layers electrically insulating the at least three conductive layers from one another. For example, one of the conductive layers can be composed of a different material than the other two of the conductive layers. The conductive layers can be composed of (i) aluminum, (ii) gold, (iii) copper or (iv) polysilicon, and/or the at least three conductive layers can be composed at least partially of (i) aluminum, (ii) gold, (iii) copper or (iv) polysilicon. The insulating layers can be composed of (i) silicon oxide, (ii) silicon nitride and/or (iii) aluminum oxide.

Disclosed are ultrathin layers of group II-VI semiconductors, group II-VI semiconductor superlattice structures, photovoltaic devices incorporating the layers and superlattice structures and related methods. The superlattice structures comprise an ultrathin layer of a first group II-VI semiconductor alternating with an ultrathin layer of at least one additional semiconductor, e.g., a second group II-VI semiconductor, or a group IV semiconductor, or a group III-V semiconductor.

A device for guiding and absorbing electromagnetic radiation, the device including: absorbing means for absorbing the electromagnetic radiation; and a coupled to the absorbing means for guiding the electromagnetic radiation to the absorbing means, wherein the waveguide and the absorbing means are formed from a structure including a first cladding layer, a second cladding layer over the first cladding layer, and a quantum-well layer between the first and second cladding layers, the quantum-well layer being formed of a material having a different composition to the first and second cladding layers, wherein the thickness and the composition of the quantum-well layer is optimised to provide an acceptable level of absorption of electromagnetic radiation in the waveguide while providing an appropriate band gap for absorption of the electromagnetic radiation in the absorbing means.

A quantum well device includes a first layer of a first two-dimensional material, a second layer of a second two-dimensional material, and a third layer of a third two-dimensional material disposed between the first layer and second layer. The first layer, the second layer, and the third layer are adhered predominantly by van der Waals force.

Dual-band barrier infrared detectors having structures configured to reduce spectral crosstalk between spectral bands and/or enhance quantum efficiency, and methods of their manufacture are provided. In particular, dual-band device structures are provided for constructing high-performance barrier infrared detectors having reduced crosstalk and/or enhance quantum efficiency using novel multi-segmented absorber regions. The novel absorber regions may comprise both p-type and n-type absorber sections. Utilizing such multi-segmented absorbers it is possible to construct any suitable barrier infrared detector having reduced crosstalk, including npBPN, nBPN, pBPN, npBN, npBP, pBN and nBP structures. The pBPN and pBN detector structures have high quantum efficiency and suppresses dark current, but has a smaller etch depth than conventional detectors and does not require a thick bottom contact layer.