Comparison of pyrite thin films obtained from Fe and natural pyrite powder

Pyrite thin films have been prepared by two different procedures: by sulphurating thermally evaporated iron films and by flash evaporating natural FeS₂ powder. The structural, morphological, electrical and optical properties of both kinds of films are compared and the influence of the sulphuration conditions studied. The films directly evaporated from pyrite powder show higher absorption coefficients and better photoactive response than those prepared from iron. Sulphuration of the films is always required in order to improve the crystallinity and decrease the density of sulphur vacancies generated by these methods.