Study of structural, morphological and optical properties of S and Cu co-doped SnO sub(2) nanostructured thin films prepared by spray pyrolysis

We have established the effect of copper dopant concentration (Cu/Sn = 0-30 at.%) on the structural, morphological and optical properties of SnO sub(2): S films grown on glass substrate using a spray pyrolysis technique. According to the experimental evidence and data analysis, we found that the polycrystalline layers in undoped condition mainly consist of mixed phases such as SnS sub(2) and SnO sub(2), whilst in doped ones, Cu sub(2)SnS sub(3) and Cu sub(4)SnS sub(4) phases are dominant. With increasing Cu concentration, a decrease in the grain size with a change in the shape of the grains is observed. Optical measurement analysis showed that these films have a direct band gap energy of about 2.98-3.59 eV.