Formation of pyrite (FeS2) thin films by thermal sulfurization of dc magnetron sputtered iron

Abstract

Iron films deposited by direct current magnetron sputtering onto glass substrates were converted into FeS2 films by thermal sulfurization. Experiments were carried out to optimize the sulfurization process, and the formation of FeS2 thin films was investigated under different annealing temperatures and times. High quality FeS2 films were fabricated using this process, and single phase pyrite films were obtained after sulfurization in a sulfur and nitrogen atmosphere at 450 °C for 1 h. Film crystallinity and phase identification were determined by using x-ray diffraction. The cubic phase pyrite films prepared were p-type, and scanning electron microscopy studies exhibited a homogeneous surface of pyrite. The authors have found that the best Ohmic contact for their pyrite thin films, using inexpensive metals, was Ni. The following were chosen for the study: Al, Mo, Fe, and Ni, and the one that led to the lowest resistance, 333 Ω, was Ni.