Abstract: A thin film photovoltaic device having first layer of copper indium selenide, a second layer of cadmium sulfide having a thickness less than 2500 angstroms, and a third layer of conducting wide bandgap semiconductor such as zinc oxide. The transparent third layer allows good transmission of blue light to the junction region while fully depleting the junction area to improve device voltage.

Abstract: A process of forming a compound semiconductive material having a plurality of constituent elements comprising electrodepositing a plurality of such constituent elements and subsequently heating the deposits to produce the desired semiconductive material.

Abstract: At least two constituent elements of a semiconductor compound are deposited in varying proportions by magnetron sputtering to produce a film having a preselected concentration gradient of the constituent elements. The film can be heat treated during or after deposition to diffuse the constituent elements within the film and enhance growth of a desired film structure. The sputtering step may be performed using a planar magnetron having a plurality of continuous magnetically enhanced sputtering cathodes extending about a common axis. Each of the cathodes includes a source structure containing at least one of the constituent elements, and provision for applying electrical power to the source structure to sputter the constituent element at a controlled rate. If one of the elements is difficult to control in the deposition process, it can be sputtered from a cathode made up of a stable alloy of the element and another constituent of the film. For example, when the semiconductor compound is CuInSe.sub.

Abstract: A method for refining silicon to produce a high purity silicon product for re-use in industries which demand high purity silicon starting material, comprising vacuum refining said silicon to remove gaseous CO and SiO followed by mixing with an effective fluxing material of at least one fluoride of alkali metals and/or alkaline earth metals, heating the mixture at a temperature and time sufficient to produce a molten silicon phase and a slag phase, and separating the slag from the silicon for recovery of the silicon for re-use.