Growth and microstructure analysis of CdS films

The high-quality CdS films was fabricated in common ammines solution of CdSO₄ and SC(NH₂)₂ by the CBD technology, and was characterized by the SEM, XRD and UV-Vis-NIR spectrum analysis. It was found that the quality of CBD-CdS films was dependent on the NH₃ concentration. Higher NH₃ concentration led to the formation of the incoherent and unfastened film, and higher S^2- and Cd²⁺ concentration tend to increase the size of CdS colloidal particles, but increasing S^2- and Cd²⁺ concentration ratio([S^2-]/[Cd²⁺]) will decrease the size of CdS colloidal particles under the same NH₃ concentration. It was also found that the peak position of the transmittances of the CdS films was dependent on the size of CdS colloidal particles. Decreasing of the size will cause the blue-shift. The overage transmittances was slightly influenced by the NH₃ concentration. Meanwhile, the CBD was improved by promoting the films thickness optimization to the colloidal particle size optimization.