Electrodeposition and characterization of CdSe semiconductor thin films

The electrodeposition of cadmium selenide alloy on glassy carbon and gold electrodes has been studied by electrochemical techniques. Potentiostatic I-t transients were recorded to obtain the nucleation mechanism, while cyclic voltammetry was used to characterize the system. Structural information on the electrodeposited layers was obtained by X-ray diffraction. The experimental results clearly show that the deposition of cadmium selenide alloy on glassy carbon and gold electrodes is a diffusion-controlled process. The nucleation is progressive, and the number of nucleation sites decreases with increasing bath temperature. The deposition of CdSe alloy results in well-defined crystals with hexagonal shape. The films were characterized by optical absorption and electrical resistivity measurements. Films showed a direct band gap of 3.56 eV.