ON THE MECHANISM OF THE CATHODIC ELECTRODEPOSITION OF CADMIUM TELLURIDE

The cathodic electrodeposition of cadmium telluride from aqueous solut ions has been studied by cyclic voltammetry and potential step techniq ues at stationary and rotating electrodes. A new theoretical model of the deposition Process has been proposed for the case where the substr ate is completely covered with CdTe. It is based on the assumption tha t Cd atoms are only incorporated at Te sites and Te atoms at Cd sites. As a consequence, deposition rates are determined by surface coverage terms as well as by charge and mass transfer Unusual nonsteady state effects have been observed during perturbation of the electrode potent ial or mass-transfer rate. These effects have been explained successfu lly by the theory in terms of the relaxation of surface adatom coverag es.