The invention relates to a process for fabricating an optoelectronic device (1) comprising a plurality of diodes (40), comprising the following steps: providing a readout substrate (10) containing a readout circuit (12) and having a growth face defined by a plurality of conductive segments (20) that are separate from one another and connected to the readout circuit (12); producing, on the growth face, a plurality of nucleation segments (30) made of a two-dimensional crystalline material, which segments are separate from one another, said segments resting in contact with the conductive segments (20); producing, by epitaxy from the nucleation segments (30), the plurality of diodes.

A photo detector comprises a first photo diode configured to capture visible light, a second photo diode configured to capture one of infrared light or ultraviolet light, and an isolation region between the first photo diode and the second photo diode. The photo detector is capable of capturing infrared light and ultraviolet light in addition to visible light.

A photovoltaic device is presented. The photovoltaic device includes a layer stack; and an absorber layer is disposed on the layer stack. The absorber layer comprises selenium, wherein an atomic concentration of selenium varies across a thickness of the absorber layer. The photovoltaic device is substantially free of a cadmium sulfide layer.

Disclosed herein are a radiation detector and a method of making it. The radiation detector is configured to absorb radiation particles incident on a semiconductor single crystal of the radiation detector and to generate charge carriers.. The semiconductor single crystal may be a CdZnTe single crystal or a CdTe single crystal. The method may comprise forming a recess into a substrate of semiconductor; forming a semiconductor single crystal in the recess; and forming a heavily doped semiconductor region in the substrate. The semiconductor single crystal has a different composition from the substrate. The heavily doped region is in electrical contact with the semiconductor single crystal and embedded in a portion of intrinsic semiconductor of the substrate.

Disclosed herein is a radiation detector configured to absorb radiation particles incident on a semiconductor single crystal of the radiation detector and to generate positive charge carriers and negative charge carriers in the semiconductor single crystal. The semiconductor single crystal may be a cadmium zinc telluride (CdZnTe) single crystal or a cadmium telluride (CdTe) single crystal. The radiation detector comprises a first electrical contact in electrical contact with the semiconductor single crystal and a second electrical contact surrounding the first electrical contact or the semiconductor single crystal. The first electrical contact is configured to collect the negative charge carriers. The second electrical contact is configured to cause the positive charge carriers to drift out of the semiconductor single crystal.

An inorganic nanocrystal solar cell comprising a substrate, a layer of metal, a layer of CdTe, a layer of CdSe, and a layer of transparent conductor. An inorganic nanocrystal solar cell comprising a transparent conductive substrate, a layer of CdSe, a layer of CdTe, and a Au contact. A method of spray deposition for inorganic nanocrystal solar cells comprising subjecting a first solution of CdTe or CdSe nanocrystals to ligand exchange with a small coordinating molecule, diluting the first solution in solvent to form a second solution, applying the second solution to a substrate, drying the substrate, dipping the substrate in a solution in MeOH of a compound that promotes sintering, washing the substrate with iPrOH, drying the substrate with N.sub.2, and heating and forming a film on the substrate.

Disclosed herein is a method for making a radiation detector. The method comprises forming a recess into a substrate and forming a semiconductor single crystal in the recess. The semiconductor single crystal may be a cadmium zinc telluride (CdZnTe) single crystal or a cadmium telluride (CdTe) single crystal. The method further comprises forming electrical contacts on the semi conductor single crystal and bonding the substrate to another substrate comprising an electronic system therein or thereon. The electronic system is connected to the electrical contact of the semiconductor single crystal and configured to process an electrical signal generated by the semiconductor single crystal upon absorption of radiation particles.

In a method of cleaning a substrate, a solution including a size-modification material is applied on a substrate, on which particles to be removed are disposed. Size-modified particles having larger size than the particles are generated, from the particles and the size-modification material. The size-modified particles are removed from the substrate.

A method for annealing an absorber layer is disclosed, the method including contacting a surface of the absorber layer with an annealing material provided as a gel. The annealing material comprises cadmium chloride and a thickening agent. A viscosity of the gel of the annealing material is greater than or equal to 5 millipascal seconds.

A method for producing a CdTe solar cell is provided, wherein at least the following layers are deposited on a glass substrate within a vacuum chamber: a TCO layer acting as a frontal contact; at least one CdTe layer; a thin layer of a chlorine-containing compound, and an electrically conductive layer acting as a return contact. Here, a maximally 20 nm thick passivation layer made from CdS, in which chemically non-bound oxygen is embedded, is deposited on the TCO layer prior to deposition of at least one CdTe-layer.