Preparation and properties of CdS thin films deposited by chemical bath deposition

In this work, a systematic research was on CdS crystalline structure by changing pH value of the solution and annealing treatments. CdS thin film deposited on ITO were prepared by chemical bath deposition using the reaction between CdAc2 and H2NCSNH2 at a certain bath temperature. In this reaction, NH3H2O was used to control pH value. Annealing treatments included coating CdCl2 and annealing directly. Morphological, structural and optical properties were investigated using scanning electron microscopy (SEM), X-ray diffraction and UV–vis spectrophotometer. As the pH value increased to 10.5, CdS film formed the best crystalline. Diffraction patterns were seen to sharpen and crystallite sizes were found to increase by annealing. However, the film annealed with CdCl2 had a blue shift compared with the direct annealing one, which is conducive to improve the efficiency of CdS/CdTe the solar cell.