PHOTOELECTROCHEMICAL DEPOSITION AND PROPERTIES OF THIN-FILM CADMIUM TELLURIDE.
Thin-film cadmium telluride has been deposited cathodically on titanium in a photoelectrochemical cell (PEC) using a propylene carbonate solution of Cd II and tri-n-butylphosphine telluride (BPT) at 100 degree C. Illumination of the cathode enhances the cathodic current relative to that observed during the dark process. Furthermore, the current under illumination decreases more slowly than it does for the dark process, providing thicker films in a shorter time. Under illumination, the Te:Cd ratio of the film is independent of light intensity and applied potential in the range minus 0. 8 to minus 1. 4 V (Ag-AgCl reference electrode). This ratio and the deposition current depend on the concentration of cadmium ion relative to that for BPT. Photovoltaic cells (PVC) have been fabricated. Light-to-electric-power conversion efficiencies as high as 5. 2% have been achieved thus far over small surface areas. The bandgap of the CdTe film is determined to be 1. 44 eV.