A comparative study of the physical properties of CdS, Bi2S3 and composite CdS-Bi2S3 thin films for photosensor application

Thin films of CdS, Bi2S3 and composite CdS-Bi2S3 have been deposited using modified chemical bath deposition (M-CBD) technique. The various preparative parameters were optimized to obtain good quality thin films. The as-deposited films of CdS, Bi2S3 and composite were annealed in Ar gas at 573 K for I h. A comparative study was made for as-deposited and annealed CdS, 1303 and composite thin films. Annealing showed no change in crystal structure of these as-deposited films. However, an enhancement in grain size was observed by AFM studies. In addition change in band gap with annealing was seen. A study of spectral response, photosensitivity showed that the films can be used as a photosensor. (c) 2007 Elsevier B.V. All rights reserved.