Microstructure dependent physical properties of evaporated tin sulfide films

In the field of photovoltaics, semiconductors of the III-V group such as GaAs and InP have been considered as the most efficient absorber materials due to their direct energy band gap and high mobility. In these compounds, arsenic and phosphorus are highly toxic and expensive. In this work we present systematic preparation of low cost SnS thin films and characterize these films to test their suitability for photovoltaic applications. We have observed that the films (with thickness congruent to 0.5 mu m) grown at the substrate temperature of 275 degrees C exhibit a low resistive single SnS phase and have a direct optical band gap of 1.35 eV with an absorption coefficient of similar to 10(5) cm(-1). SnS films could be alternative semiconductor materials as absorbers for the fabrication of photovoltaic devices.