Abstract: A chalcopyrite-type compound, for instance, CuInS.sub.2 or CuGaS.sub.2, is prepared by subjecting a Group I-III oxide composition, containing at least one of the Group Ib element, for instance copper (Cu), and at least one of the Group IIIb element, for instance indium (In) or gallium (Ga) to a heat treatment under a reducing atmosphere containing the Group VIb element, for instance sulfur (S) or selenium (Se), or under an atmosphere containing a reducing compound of the Group VIb element, thereby converting said oxide composition into a chalcopyrite-type compound.

Abstract: Chalcopyrite compound semiconductor thin films represented by I-III-VI.sub.2-x V.sub.x or I-III-VI.sub.2-x VII.sub.x, and semiconductor devices having a I-III-VI.sub.2 /I-III-VI.sub.2-x V.sub.x or I-III-VI.sub.2 /I-III-VI.sub.2-x VII.sub.x chalcopyrite homojunction are provided. Such chalcopyrite compound semiconductor thin films are produced by radiating molecular beams or ion beams of the I, III, VI, and V or VII group elements simultaneously, or by doping I-III-VI.sub.2 chalcopyrite thin films with VII-group atoms after the formation thereof. Pollution-free solar cells are also provided, which are formed by the steps of forming a structure of a lower electrode, a chalcopyrite semiconductor thin film, and an upper electrode and radiating accelerated ion beams of a V, VII, or VIII group element thereto.

Abstract: A I-III-VI.sub.2 chalcopyrite semiconductor film containing a Group VII element as a dopant, and methods to produce such a chalcopyrite film are provided. The chalcopyrite film of the present invention has stoichiometric composition, and electrical characteristics such as p-n conduction type, carrier concentration and the like are controlled.