R. A. Chikwenze, P. A. Nwofe and P. E. Agbo
The study reports on the comparative investigations of some selected selenides (cadmium selenide CdSe, lead selenide PbSe and copper selenide CuSe) grown using the chemical bath deposition technique, with emphasis on the influence of concentration and annealing temperatures on the structural and optical properties of the layers. The asgrown layers were deposited at a temperature of 50 oC and annealed at annealing temperatures ≤ 400oC. The layers were characterised using X-ray diffractometry (XRD) and optical spectroscopy analysis. The results show that the film thickness increased with an increase in the concentration and annealing temperatures for PbSe films. For CdSe layers, the film thickness increased up to a concentration of 0.4 M and then exhibited a marginal decrease thereafter while for CuSe a sharp increase was observed for concentrations > 0.6 M. At concentrations > 0.6 M, the crystallite size increased with an increase in concentration for CuSe layers and decreased for PbSe thin films while a marginal increase was observed for CdSe layers. The energy bandgap of the trio were found to be in the range 1.15 eV to 2.4 eV for the as-deposited layers. However, annealing the layers resulted in the decrease of the energy band gap for the PbSe layers. The range of the energy bandgap obtained in the study, suggest possible use of the layers in various optoelectronic devices
