CdS Nanofilms: effect of deposition temperature on morphology and optical band gap

Abstract

We have grown 45–60 nm thick uniform smooth cadmium sulphide (CdS) nanofilms via a chemical bath deposition technique at different deposition temperatures (Td = 50, 60, 70, 80 and 90 C) and these have been studied using x-ray diffraction, scanning electron microscopy, atomic force microscopy and a UV–Vis–NIR spectrophotometer. The growth rate increases with increasing Td up to 70 C and then decreases. The structural analysis shows that CdS nanofilms exist in cubic or polymorph phases. The surface analysis indicates that the morphology of the films changes with increasing Td. CdS nanofilms grown at Td = 70 C show high transmittance, low absorbance with a higher band gap.