Preparation and physical investigations on sprayed SnxSy thin films for solar cell applications

Thin films of tin sulphides (Sn_xS_y) were deposited on glass substrates by spray pyrolysis technique using precursor solutions of SnCl₂.2H₂O and thiourea and InC l₃ at different substrate temperatures that vary in the range of 275-375°C. The physical properties of these films were characterized by using X- ray diffraction, Field Emission Scanning Electron Microscope, UV-Visible Spectrophotometer and Photoluminescence. The XRD pattern revealed that the undoped and doped films had preferred orientation along (002) plane with hexagonal structure. FESEM micrographs had shown that morphologies of the films were changed with doping of indium. The direct energy band gap value of undoped and indium doped SnS₂ thin films were found to be 2.7 eV and 2.5 eV respectively. Photoluminescence had shown the shift in the band towards the longer wavelength.