Abstract: This invention relates to a manufacturing method of a compound semiconductor thin film derived from a metal sulfide produced by thermal decomposition of a sulfur-containing metal organic compound, the compound containing at least one functional group having at least one metal atom selected from the group consisting of copper, zinc, cadmium, mercury, and lead, and the functional group also containing at least one sulfur atom. Since the obtained metal sulfides are of high-purity and dense, they can be utilized in various photoelectric devices. Particularly, the photoelectric conversion efficiency of a CdS/CdTe system thin film compound semiconductor solar cell can be improved remarkably by employing a layer made of a CdS thin film as a window of the solar cell.

Abstract: A method for producing a purified polycarbonate resin is disclosed, comprising contacting a solid polycarbonate resin with a fluid comprising at least 70% by weight of carbon dioxide and having a temperature of 30.degree. to 120.degree. C. and a pressure of at least 10 kg/cm.sup.2. The method can effectively remove almost all the impurities contained in the polycarbonate resin within a very short period of time, thereby providing highly purified polycarbonate resin materials which are suitably used in the fields of information, electronic and medical industries.