EFFECT OF DEPOSITION PARAMETERS ON GROWTH AND CHARACTERIZATION OF CHEMICALLY DEPOSITED Cd1-XPbXS THIN FILMS

A Simple and cost effective chemical bath deposition process has been employed for the preparation of Cd1-xPbxS (x = 0.00, 0.20, 0.40, 0.60, 0.80, 1.00) thin films. Cadmium sulphate, lead sulphate and thiourea were used as the basic source materials. The effect of various preparative parameters such as bath composition, pH of the reaction solution, deposition temperature and time, speed of the substrate rotation and the complexing agent on growth process is studied and these parameters are optimized for good quality films. The colour of the 'as-deposited' thin films has changed from orange yellow to black as the composition parameter x changed from 0 to 1. The film thickness is found to be increased with increasing the composition parameter x from 0 to 1. The X-ray diffraction (XRD) studies revealed that films are polycrystalline in nature and exhibit both cubic and hexagonal structure for pure CdS but only cubic phases for pure PbS film. The energy dispersive analysis by X-rays (EDAX) studies revealed that films are cadmium rich. The energy band gap is decreased from 2.47 eV to 0.49 eV as composition parameter 'x' is increased from 0 to 1.