Comprehensive characterization of structural, optical and electrical properties of CdS thin films annealed in air and vacuum

In this report, the influence of annealing temperature on the structural, morphological optical, and electrical properties of CdS films has been discussed. These CdS thin films were generated on a glass substrate using the thermal evaporation technique and deposited films were annealed in vacuum and air in the temperatures range of 100-400 degrees C. The structural, morphological, optical, and electrical properties were investigated by using XRD, FESEM, and UV-VIS-NIR techniques. XRD pattern showed that films were polycrystalline with hexagonal structure along with predominant to (002) plane (with space group = P63mc). The Rutherford backscattering spectra were used to confirm the thickness and stichometry of these deposited CdS thin films. EDX confirms the presence of various trace elements. The transmittance of air and vacuum annealed films was recorded up to similar to 85% in the visible region. A blue shift of the absorbance edge of CdS thin films will be useful for improving the efficiency of photovoltaic cells. Vacuum-annealed thin films showed improved and optimized resistivity and conductivity.