Growth kinetics and photoelectrochemical (PEC) performance of cadmium selenide thin films: pH and substrate effect

Cadmium selenide (CdSe) thin films have been electrochemically deposited on the stainless steel (SS) and fluorine-doped tin oxide (FTO) coated glass substrates at room temperature (27 °C). The growth kinetics of CdSe thin films was studied by using cyclic voltammetry and chronoamperometry with variation in the pH of the electrolytic bath. In addition, the influence of the substrate on the microstructural properties of CdSe is plausibly explained. The photoelectrochemical (PEC) characterization of the film has been carried out to optimize the preparative parameters. X-ray diffraction data reveal growth of the cubic phase with preferential orientation along (1 1 1) direction. Compositional analysis of the film shows nearly stoichiometric film formation at pH 2.7. Uniform film formation with nano-sized grains was seen from SEM images. Optical absorption studies reveal that the pH of the electrolytic solution has a significant effect on the band gap of the film. PEC study revealed that CdSe film deposited at pH 2.7 on SS substrate showed better photosensitivity as compared to the film deposited on FTO coated glass.