The effects of sodium tartrate concentration on the properties of CdTe thin films prepared by electrodeposition

Abstract

In this paper, we successfully fabricate compact and uniform cadmium telluride (CdTe) films on flexible nickel foils using simple electrodeposition technique and sintering in a nitrogen atmosphere. The effect of the concentration of sodium tartrate on the structures and properties of the deposited CdTe thin films are studied. Various test techniques are used to characterize the results. The results of XRD analysis show that the highest crystallinity film is obtained when the added sodium tartrate concentration is 0.05 M. With the increase of sodium tartrate concentration, the composition of the film gradually changes from Te-rich to Cd-rich, and the thickness of the film becomes thin gradually. We also find that the CdTe thin film prepared under 0.05 M sodium tartrate shows the best optical and optoelectronic properties. Thus, a moderate amount of sodium tartrate is added into an acidic solution as surfactant for CdTe thin film fabrication. Moreover, sodium tartrate is easily volatilized from the film during the annealing process because of its small molecular weight, which can prevent the carbon precipitation.