Structural transition in II-VI nanofilms: Effect of molar ratio on structural, morphological, and optical properties

Cadmium sulphide nanofilms have been deposited by chemical bath deposition technique on glass substrates. The effect of S/Cd molar ratio on the structural, morphological, and optical properties of CdS nanofilms has been investigated. Structural parameters have been analyzed using x-ray diffractometer. Scanning electron microscope and energy dispersive x-ray analyzer have been used to study surface morphology and elemental composition of nanofilms, respectively. The optical properties of the nanofilms have been studied for varying S/Cd molar ratio. The variation in S/Cd molar ratio induces reorientation in lattice structure of the nanofilms and a phase transition has been observed with changing molar ratios. The modification in properties with varying S/Cd ratio has been discussed in terms of quantum confinement and compared with theoretical results based on effective mass approximation and tight binding model.