Mechanism of electrodeposition of cadmium selenide from solution

Abstract

The mechanism of the electrodeposition of CdSe from selenosulfite and cadmium–NTA complex has been studied by analysis of the Tafel regions of linear sweep voltammograms. The Tafel plots were linear for up to 20% of the peak height, and were used to calculate the dependence of the reduction rate on the concentration of each of the reactants. The electron transfer process was found to be first order with respect to [Formula: see text] and zero order with respect to each of the other reactants. These results are consistent with a two-step reduction of [Formula: see text]to Se2−, followed by precipitation of CdSe. The reduction of Cd(NTA)− to cadmium metal appears to be blocked or inhibited in the presence of [Formula: see text], resulting in CdSe films of nearly perfect stoichiometry to be deposited.