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 embodiments include CdS/CdTe PV devices (100) having a back contact (110,112) with oxygen gettering capacity. Also disclosed are back contact structures (110, 112) and methods of forming a back contact in a CdS/CdTe PV device (100). The described contacts and methods feature a contact having a contact interface layer (100) comprising a contact interface material, a p-type dopant and a gettering metal.

Methods of making a semiconductor layer from nanocrystals are disclosed. A film of nanocrystals capped with a ligand can be deposited onto a substrate; and the nanocrystals can be irradiated with one or more pulses of light. The pulsed light can be used to substantially remove the ligands from the nanocrystals and leave the nanocrystals unsintered or sintered, thereby providing a semiconductor layer. Layered structures comprising these semiconductor layers with an electrode are also disclosed. Devices comprising such layered structures are also disclosed.

A semiconductor nanoparticle dispersion is provided. The semiconductor nanoparticle including a plurality of semiconductor nanoparticles having a radius equal to or larger than an exciton Bohr radius; and a solvent dispersed with the plurality of semiconductor nanoparticles.

Halometallate-capped semiconductor nanocrystals and methods for making the halometallate-capped semiconductor nanocrystals are provided. Also provided are methods of using solutions of the halometallate-capped semiconductor nanocrystals as precursors for semiconductor film formation. When solutions of the halometallate ligand-capped semiconductor nanocrystals are annealed, the halometallate ligands can act as grain growth promoters during the sintering of the semiconductor nanocrystals.

The present disclosure provides systems and methods for depositing an alkaline metal layer on an absorber to generate a copper-poor region at a surface of the absorber. The copper-poor region provides an increased efficiency over non-treated absorbers having copper-rich surfaces. The alkaline metal layer may be deposited by any suitable deposition method, such as, for example, a wet deposition method. After the alkaline metal layer is deposited, the absorber is annealed, causing the alkaline metal layer to interact with the absorber to reduce the copper-profile of the absorber at the interface between the alkaline metal layer and the absorber.

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 semiconductor crystal substrate includes: a crystal substrate whose principal surface is inclined relative to a (001) plane; and a superlattice structure layer including a first superlattice formation layer and a second superlattice formation layer, wherein the first superlattice formation layer is formed of Ga.sub.1-x1In.sub.x1As.sub.y1Sb.sub.1-y1 (0x10.1, 0y10.1), and a value of a standard deviation to a mean value of atomic step widths in an inclination direction is equal to or greater than 0 and equal to or smaller than 0.20, and the second superlattice formation layer is formed of Ga.sub.1-x2In.sub.x2As.sub.y2Sb.sub.1-y2 (0.9x21, 0.9y21), and a value of a standard deviation to a mean value of atomic step widths in an inclination direction is equal to or greater than 0 and equal to or smaller than 0.40.

A method of making a photovoltaic cell includes providing a metal oxide substrate. The substrate is at least translucent to light. The substrate is directed through a deposition chamber. A semiconductor is deposited over a first major surface of the substrate. The semiconductor includes a polycrystalline p-type layer. The semiconductor is exposed to a chlorine-containing compound or a chlorine molecule. A second electrode layer is provided over the semiconductor.