Polycrystalline and single phase FeS2 films grown by chemical bath deposition

Abstract

Recently, iron disulphide (FeS2) has been considered as a potential solar absorber material due to several factors. These include more abundance and less toxicity of the elements involved, suitable energy band gap (0.95 eV) with high optical absorption coefficient and sufficiently long minority carrier diffusion length to produce short circuit currents >30 mA. Thin films of FeS2 have been grown by a variety of physical as well as chemical methods. In this work, a simple wet chemical process, chemical bath deposition, was used to synthesise FeS2 films using iron sulphate and thiourea as precursors. Ammonia was used in combination with EDTA as a novel complexing agent to form the layers for the first time. The films were deposited using different bath temperatures (Tb) that vary in the range 50°C-70°C, keeping the other deposition parameters constant. The chemical and physical properties of the films were investigated using appropriate techniques.