A photodetector comprising a photoabsorber, comprising a doped semiconductor, a contact layer comprising a doped semiconductor and a barrier layer comprising a charge carrier compensated semiconductor, the barrier layer compensated by doping impurities such that it exhibits a valence band energy level substantially equal to the valence band energy level of the photo absorbing layer and a conduction band energy level exhibiting a significant band gap in relation to the conduction band of the photo absorbing layer, the barrier layer disposed between the photoabsorber and contact layers. The relationship between the photo absorbing layer and contact layer valence and conduction band energies and the barrier layer conduction and valance band energies is selected to facilitate minority carrier current flow while inhibiting majority carrier current flow between the contact and photo absorbing layers.

The invention relates to a photo bode type structure (comprising: a support (100) including at least one semiconductor layer, the semiconductor layer (120) including of a first semiconductor zone (10) of a first type of conductivity and a mesa (130) in contact with the semiconductor layer (120). The mesa (130) includes of a second semiconductor zone (20), known as absorption zone, said second semiconductor zone (20) being of a second type of conductivity. The second semiconductor zone has a concentration of majority carriers such that the second semiconductor zone (30) is depleted in the absence of polarization of the structure (1). The structure (1) further comprises a third semiconductor zone (30) of the second type of conductivity made of a third material transparent in the absorbed wavelength range. The third semiconductor zone (30) is interposed between the first and the second semiconductor zones (10, 20) while being at least partially arranged in the semiconductor layer (120). The invention also relates to component and a method for manufacturing such a structure (1).

A photodetector comprising a photoabsorber, comprising a doped semiconductor, a contact layer comprising a doped semiconductor and a barrier layer comprising a charge carrier compensated semiconductor, the barrier layer compensated by doping impurities such that it exhibits a valence band energy level substantially equal to the valence band energy level of the photo absorbing layer and a conduction band energy level exhibiting a significant band gap in relation to the conduction band of the photo absorbing layer, the barrier layer disposed between the photoabsorber and contact layers. The relationship between the photo absorbing layer and contact layer valence and conduction band energies and the barrier layer conduction and valance band energies is selected to facilitate minority carrier current flow while inhibiting majority carrier current flow between the contact and photo absorbing layers.

An epitaxial wafer which allows manufacture of a photodiode having suppressed dark current and ensured sensitivity, and a method for manufacturing the epitaxial wafer, are provided. The epitaxial wafer of the present invention includes: a III-V semiconductor substrate; and a multiple quantum well structure disposed on the substrate, and including a plurality of pairs of a first layer and a second layer. The total concentration of elements contained as impurities in the multiple quantum well structure is less than or equal to 5×10.sup.15 cm.sup.−3.

A photovoltaic device includes a substrate structure and a p-type semiconductor absorber layer. A photovoltaic device may include a CdSeTe layer. A process for manufacturing a photovoltaic device includes forming a CdSeTe layer over a substrate. The process includes forming a p-type cadmium selenide telluride absorber layer.

Disclosed are a mercury cadmium telluride-black phosphorus van der Waals heterojunction infrared polarization detector and a preparation method thereof. The structure of the detector from bottom to top comprises a substrate, a mercury cadmium telluride material, an insulating layer, a two-dimensional semiconductor black phosphorus, and metal electrodes. First, growing the mercury cadmium telluride material on the substrate, removing part of the mercury cadmium telluride by ultraviolet lithography and argon ion etching, filling with aluminum oxide as the insulating layer using an electron beam evaporation method, transferring the two-dimensional semiconductor material black phosphorus at the junction of mercury cadmium telluride and an insulating layer assisted by a polypropylene carbonate film, and preparing the metal source-drain electrodes by electron beam lithography technology combined with the lift-off process to form the mercury cadmium telluride-black phosphorus van der Waals heterojunction infrared polarization detector.

Embodiments of a photovoltaic device are provided herein. The photovoltaic device can include a layer stack and an absorber layer disposed on the layer stack. The absorber layer can include a first region and a second region. Each of the first region of the absorber layer and the second region of the absorber layer can include a compound comprising cadmium, selenium, and tellurium. An atomic concentration of selenium can vary across the absorber layer. The first region of the absorber layer can have a thickness between 100 nanometers to 3000 nanometers. The second region of the absorber layer can have a thickness between 100 nanometers to 3000 nanometers. A ratio of an average atomic concentration of selenium in the first region of the absorber layer to an average atomic concentration of selenium in the second region of the absorber layer can be greater than 10.

According to the embodiments provided herein, a method for doping an absorber layer can include contacting the absorber layer with an annealing compound. The annealing compound can include cadmium chloride and a group V salt comprising an anion and a cation. The anion, the cation, or both can include a group V element. The method can include annealing the absorber layer, whereby the absorber layer is doped with at least a portion of the group V element of the annealing compound.

Provided is a stable CdZnTe monocrystalline substrate having a small leakage current even when a high voltage is applied and having a lower variation in resistivity with respect to variations in applied voltage values. A semiconductor wafer comprising a cadmium zinc telluride monocrystal having a zinc concentration of 4.0 at % or more and 6.5 at % or less and a chlorine concentration of 0.1 ppm by mass or more and 5.0 ppm by mass or less, wherein the semiconductor wafer has a resistivity of 1.0×10.sup.7 Ωcm or more and 1.0×10.sup.8 Ωcm or less when a voltage of 900 V is applied, and wherein a ratio (variation ratio) of the resistivity at application of 0 V to the resistivity at application of a voltage of 900 V is 20% or less.

Solar cells, absorber structures, back contact structures, and methods of making the same are described. The solar cells and absorber structures include a pseudomorphically strained electron reflector layer.