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. •FeS2 films were prepared based on successive ionic layer adsorption & reaction method.•XPS analysis revealed the formation mechanism of FeS2 films.•The FeS2 thin films are of pure pyrite structure and p-type conductivity.•The FeS2 thin films have suitable optical and electrical properties for solar cells.