Abstract: Chemical bath deposition (CBD) has proved top be the most favorable method for application of a buffer layer to semiconductor substrates, for example, chalcopyrite thin-film solar cells, whereby previously cadmium sulphide (CdS) was deposited and as cadmium is a highly toxic heavy metal, alternatives have been required. According to the invention, the semiconductor substrate is dipped in a solution for approximately 10 minutes, produced by the dissolution of zinc sulphate (0.05-0.5 mol/l) and thiourea (0.2 to 1.5 mol/l) in distilled water at a temperature being held essentially constant throughout said period. For the first time, the ZnS layer permits comparable or higher efficiencies than conventionally only achieved with toxic cadmium compounds. The method is hence much more environmentally-friendly with the same result.

Abstract: A chemical bath deposition method of depositing on a semiconductor substrate a layer of zinc sulfide by dipping the semiconductor substrate into an aqueous solution of zinc sulfate and thiourea and ammonia.

Abstract: Photoactive pyrite layers, whose preparation and use represent a commercially highly interesting alternative to materials hitherto in common use. The semiconductor material chiefly used until now, e.g. for solar cells, is silicon. However, its costs of manufacture are too high to allow solar cells to be made at favorable cost. The significance of the disclosure and development of pyrite as a semiconductor material, especially for solar cells, lies in the fact that it is plentifully occurring and cheap, as well as environmentally compatible. Pyrite (iron pyrites, FeS.sub.2) can be used as a photoactive material in solar cells and in optoelectronic components. It is possible to use both naturally occurring pyrite, after a material treatment to improve the photosensitivity, as well as synthetically produced, single-crystal and polycrystalline pyrite.