Effects of CeO2 Dopant on Structural and Optical Properties of ZnO Thin Films Prepared by RF Sputtering

ZnO thin films with and without doping of CeO2 (3%) were deposited on SiO2 substrates by using RF sputtering technique. X-ray diffraction studies revealed that as deposited films at 400 degrees C showed polycrystalline phase with a hexagonal wurtzite configuration. The effect of deposition conditions on the roughness of the interfaces were characterised by using AFM. RMS roughness and average roughness were analyzed at several regions of the surface. The average grain size of doped ZnO films is smaller than that of undoped films. The thickness of the thin films was measured by taking cross-sectional view of thin films through FE-SEM. The optical, absorption, and transmission properties of thin films were further determined by UV-IR spectrophotometer. The average transmittance of 70-90% for various sputtering gas ratio was observed with an average reflectivity of nearly 18%. The band gap of ZnO thin films was found to vary in the range of 3.129 to 3.093 eV.