Changes on the structural and optical properties of ZnS films by chemical bath deposition technique on annealing in air atmosphere

ZnS films were prepared by chemical bath deposition (CBD) at 25 °C without stirring. The energy gap of the films was found to decrease by annealing. The $\alpha$ values were found to increase with annealing. Excitonic absorption was seen in thinner film. There are definite optimum time intervals in annealing beyond which no detectable optical changes occur. This was seen both 300 °C and 450 °C annealing experiments with 0.15 $\mu m$ & 0.6 film thicknesses.ZnS films were prepared by chemical bath deposition (CBD) at 25 °C without stirring. The energy gap of the films was found to decrease by annealing. The $\alpha$ values were found to increase with annealing. Excitonic absorption was seen in thinner film. There are definite optimum time intervals in annealing beyond which no detectable optical changes occur. This was seen both 300 °C and 450 °C annealing experiments with 0.15 $\mu m$ & 0.6 film thicknesses