The invention refers to a method for activating an absorber layer of a semi-finished thin-film solar cell. The absorber layer comprises CdSe.sub.xTe.sub.1-x, CdSe, CdS or CdTe. The method comprises the steps of providing a semi-finished thin-film solar cell with an absorber layer comprising a CdSe.sub.xTe.sub.1-x, layer or comprising at least two layers selected from CdS, CdTe, ZnTe, CdSe, forming a polyvinylchloride film on a surface of the absorber layer, and performing a heat treatment of the semi-finished thin-film solar cell with the polyvinylchloride film on it, wherein the temperature is in the range of 300 C. to 500 C.

Photovoltaic cells, photovoltaic devices, and methods of fabrication are provided. The photovoltaic cells include a transparent substrate to allow light to enter the photovoltaic cell through the substrate, and a light absorption layer associated with the substrate. The light absorption layer has opposite first and second surfaces, with the first surface being closer to the transparent substrate than the second surface. A passivation layer is disposed over the second surface of the light absorption layer, and a plurality of first discrete contacts and a plurality of second discrete contacts are provided within the passivation layer to facilitate electrical coupling to the light absorption layer. A first electrode and a second electrode are disposed over the passivation layer to contact the plurality of first discrete contacts and the plurality of second discrete contacts, respectively. The first and second electrodes include a photon-reflective material.

The present invention relates to a method for preparing an aqueous or hydro-alcoholic colloidal solution of metal chalcogenide amorphous nanoparticles notably of the Cu.sub.2ZnSnS.sub.4 (CZTS) type and to the obtained colloidal solution.

The present invention also relates to a method for manufacturing a film of large-grain crystallized semi-conducting metal chalcogenide film notably of CZTS obtained from an aqueous or hydro-alcoholic colloidal solution according to the invention, said film being useful as an absorption layer deposited on a substrate applied in a solid photovoltaic device.

A photoconductive device that generates or detects terahertz radiation includes a semiconductor layer; a structure portion; and an electrode. The semiconductor layer has a thickness no less than a first propagation distance and no greater than a second propagation distance, the first propagation distance being a distance that the surface plasmon wave propagates through the semiconductor layer in a perpendicular direction of an interface between the semiconductor layer and the structure portion until an electric field intensity of the surface plasmon wave becomes 1/e times the electric field intensity of the surface plasmon wave at the interface, the second propagation distance being a distance that a terahertz wave having an optical phonon absorption frequency of the semiconductor layer propagates through the semiconductor layer in the perpendicular direction until an electric field intensity of the terahertz wave becomes 1/e.sup.2 times the electric field intensity of the terahertz wave at the interface.

A method for forming a thin film having sulfide single-crystal nanoparticles includes dropping a sulfide precursor solution on the surface of a Group VI absorption layer, and then performing thermal decomposition on the sulfide precursor solution under a predetermined temperature to form a thin film consisting of sulfide single-crystal nanoparticles on the surface of the Group VI absorption layer.

A photovoltaic cell is provided that enables cost reduction and stable operation with a simple configuration and enhances conversion efficiency by a new technology of forming an energy level in a band gap. In the photovoltaic cell, a substrate, a conductive first electrode, an electromotive force layer, a p-type semiconductor layer, and a conductive second electrode are laminated, electromotive force is generated by photoexciting the electron in the band gap of the electromotive force layer by light irradiation, the electromotive force layer is filled with an n-type metal oxide semiconductor of fine particles coated by an insulating coat, a new energy level is formed in a band gap by photoexcited structural change caused by ultraviolet irradiation, and efficient and stable operation can be performed by providing a layer of an n-type metal oxide semiconductor between the first electrode and the electromotive force layer.

An apparatus and method pertaining to a perpetual energy harvester. The harvester absorbs ambient infrared radiation and provides continual power regardless of the environment. The device seeks to harvest the largely overlooked blackbody radiation through use of a semiconductor thermal harvester.

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.

Provided are photovoltaic devices with polycrystalline type II-VI semiconductor absorber materials including n-type absorber compositions and having p-type hole contact layers are described herein. Methods of treating semiconductor absorber layers and forming hole contact layers are described.

A process for impurification of semiconductor materials, comprising adjacent compensated codoping comprising: (a) providing a multicomponent host material AEGJ . . . ; (b) selecting two impurities Q and X codopants elements under the following scheme: (i) considering the host A and G, impurity Q is the chemical element with atomic number Z.sub.A1 and impurity X is the chemical element with atomic number Z.sub.G+1; or impurity Q is the chemical element with atomic number Z.sub.A+1 and impurity X is the chemical element with atomic number Z.sub.G1; or (ii) considering the host A and G, impurity Q is the chemical element with atomic number Z.sub.A2 and impurity X is the chemical element with atomic number Z.sub.G+2; or impurity Q is the chemical element with atomic number Z.sub.A+2 and impurity X is the chemical element with atomic number Z.sub.G2; or (iii) considering the host A and G, impurity Q is the chemical element with atomic number Z.sub.A1 and impurity X is the chemical element with atomic number Z.sub.G+2; or impurity Q is the chemical element with atomic number Z.sub.A+2 and impurity X is the chemical element with atomic number Z.sub.G1; and (c) performing the host adjacent codoping process with the selected impurities.