One or more embodiments of the present invention relate to structures obtained by methods (a) for growing a film by an intermixing growth process, or (b) by depositing a film, which film includes chalcogenides of copper and/or silver (but excluding oxides), such as, for example, copper sulfide (CuS.sub.X and/or Cu.sub.2S.sub.X, where 0.7.ltoreq.X.ltoreq.1.3; and X=1.0 for stoichiometric compounds).