Influence of film and deposition parameters on the electrical conduction in CdSexTe1-x thin films.

Abstract

The effects of film thickness, deposition rate, deposition temperature (substrate temperature), and heat treatment in vacuum as well as in different ambients on electrical conduction in ${\mathrm{CdSe}}_{\mathit{x}}$${\mathrm{Te}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$ thin films were investigated. Films deposited at optimum conditions resulted in good-quality films, whereas those deposited at suboptimum conditions formed films with an excess or a deficiency of one of the elements. This is explained by the variation in the condensation of the elements under different deposition conditions. The percentage of CdSe in the pseudobinary alloy influenced the film resistance considerably since selenium vacancy in the film influenced the film resistance. The transmission electron micrographs of the films showed that the crystallite size increased with an increase in film thickness and substrate temperature and decreased with an increase in deposition rate. Seto's polycrystalline model was used to explain the conduction mechanism in the films above 300 K.