Effect of annealing temperature on structural and Raman spectroscopy analysis of nanostructured CdS thin films

Abstract

Nanocrystalline CdS thin films were deposited on glass substrates using the sol-gel spin coating method. The structural properties and surface morphology of the CdS thin films were characterized by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Atomic force microscopy (AFM). XRD studies revealed that all the films exhibit cubic structure with a (1 1 1) preferential orientation. The diffraction peak (1 1 1) shifts towards higher 20 value with increasing annealing temperature from 150 oC to 350 oC. The Raman spectra shows the intense and broad peaks at ∼302 and ∼603.5cm-1 which are assigned to fundamental optical phonon mode (LO) and first over tone mode (2LO) of CdS.