Influence of precursor solution volume on the properties of tin disulphide (SnS2) thin films prepared by nebulized spray pyrolysis technique

Tin disulphide (SnS2) thin films have been deposited with various precursor solution volumes (5-25 ml) by nebulized spray pyrolysis technique onto glass substrates. The X-ray diffraction studies revealed that the as-deposited SnS2 thin films were polycrystalline in nature and having a hexagonal structure with a single preferential orientation along (001) plane. SEM analysis revealed that all the thin films had platelet-like grains. The EDAX analysis confirmed the presence of tin and sulphur. Multiple interference effect was predominant in all these thin films in the wavelength region of 500-1100 nm. Direct band gap values were found to decrease up to 2.67 eV with the increase in precursor solution volumes from 5 to 20 ml and increased further. All the SnS2 thin films were found to be n-type semiconductors. The better conductivity and mobility noticed at the precursor solution volume of 20 ml are explained by carrier concentration and crystallites. The Activation energy of these films was determined by plotting a graph between log (resistivity) versus reciprocal temperature using a four-probe method.