Studies on the effects of annealing on the structural and optical properties of nanocrystalline ZnCdS thin films

Abstract

Zinc Cadmium Sulphide (ZnCdS) is a ternary direct band gap semiconducting material having potential applications in different opto-electronic devices. The deposition temperature can be effectively used to enhance the structure and optical properties of the films. In this paper, we have investigated the effect of air annealing on the various properties of ZnCdS films. A nanocrystalline ZnCdS thin film was successfully deposited on molybdenum substrate and the effect of annealing on structural, morphological, and optical properties were studied. The main impact was found to be slightly increase in crystallite size which effectively reduced the defects. It is observed that deposited film annealed at higher temperature provide a smooth and flat texture suited for optoelectronic applications. SEM photographs reveals the deposited grains are well connected and uniformly distributed over the surface. The experimental results show that the energy gap of the films is not much affected by the annealing temperature and varies from 2.6 eV to 2.7 eV. However, the oxygen annealing improves crystalline structure.