Paper Title
Effect of S: Fe Molar Ratios on the Direct Formation of Nanocrystalline Pyrite Fes2 Thin Films by Chemical Spray Pyrolysis Under a Low Substrate Temperature (<300 °C) and their Optical Properties

Abstract
The FeS2 films were deposited by using the spray pyrolysis method using mixed aqueous solutions of CH4N2S and FeCl3, with different S:Femolar ratios. The homogeneous FeS2 nanocrystalline films with good crystallinity were synthesized. The structure, composition, and properties of these filmswere verysensitive to the S:Femolar ratios. The direct transition of the pyrite FeS2films were about 0.9-1.25 eV. High absorption coefficients andsuitable band gapswere observed. Keywords- Thin Films; Nanocrystalline Materials;Chemical Spray Pyrolysis; Optical Absorption.