Fabrication of pyrite FeS2 thin films by sulfurizing oxide precursor films deposited via successive ionic layer adsorption and reaction method

Iron pyrite (FeS2) is a naturally abundant and nontoxic semiconductor that can potentially be used in photovoltaic devices. In this report, pure pyrite FeS2 thin films with homogeneous morphology and ideal composition are fabricated by sulfurizing Fe2O3 precursor thin films deposited via successive ionic layer adsorption and reaction method. The formation mechanism of FeS2 is identified by X-ray photoelectron spectroscopy. The optical and electrical (including photoelectrochemical) measurements show that the prepared pyrite FeS2 thin films have high absorption coefficient, suitable band gap, p-type conductivity and good photo-electrical conversion ability.