Irregularities at the interface in Cu_xS/CdS thin films can be controlled by annealing CdS film prior to chemiplating. The interlayer formed on CdS films annealed at 200°C is comparatively smooth. In CdS films annealed at higher temperatures, the interlayer is rather thick and the CdS intrusions into this layer are thin. An ellipsometric technique is used for this study and the effective medium theory which is utilized to interpret the results is based on the difference in reaction rate in the grains as well as grain boundaries during chemiplating.

The influence of annealing temperature on photoconductivity of spray pyrolysed CdS films has been investigated. The annealing of films at 373K resulted in maximum photoconductivity. The photoconductivity at all wavelengths was found to decrease with increase of annealing temperature and became a minimum at 473K. For films annealed at or above 523K, the photoconductivity for wavelengths ⩾560 nm decreased considerably. The results are discussed with the help of ellipsometric data, visible and IR spectra of these samples. Also the variation in photoconductivity of these samples were studied during heating to analyse the effect of trapping.

CdS thin films prepared by chemical bath deposition technique are characterized using X-ray diffraction, optical absorption spectrometry and scanning electron microscopy. The results of the annealing studies on the films in flowing argon and air atmospheres are also presented in this paper. The resistivity has drastically reduced on annealing in flowing air which is attributed to the partial conversion of CdS to CdO phase.

Top layer of spray pyrolyzedn-type CdS has been converted intop-type by diffusion of copper which resulted in the formation of homojunction. This is achieved by annealing CdS/Cu bilayer film. The nature of diffusion of copper atoms into CdS has been studied using auger electron spectroscopy (AES).