Chemical bath deposition of ZnS thin films and modification by air annealing

TLDR: In this article, the authors demonstrate the deposition of ZnS thin films with a thickness of 0.04 to m at temperatures ranging from 25 to C from chemical baths comprising zinc sulphate, triethanolamine and thioacetamide at pH of about 10.

Abstract: We demonstrate the deposition of ZnS thin films with a thickness of 0.04 to m at temperatures ranging from 25 to C from chemical baths comprising zinc sulphate, triethanolamine and thioacetamide at pH of about 10. The as-deposited films do not show crystallinity, are very resistive (conductivity ) and possess no photosensitivity. Annealing of the films in air at 450 to C for 1 - 2 h leads to partial conversion of the ZnS films to ZnO films. This is accompanied by an increase in the photoconductivity by more than six orders of magnitude. The optical bandgap is >3.85 eV in the as-prepared films; after annealing in air the value drops to about 3.7 eV.