Characterization of zinc telluride thin films for photoelectrochemical applications

Zinc telluride (ZnTe) semiconducting thin films were prepared by cathodic electrodeposition on to tin-oxide-coated glass and titanium substrates. Studies revealed that stoichiometric ZnTe films were synthesized by maintaining the deposition potential, solution pH, zinc concentration, and bath temperature as -1.1 V versus a saturated calomel electrode, 3.5 +/- 0.01, 0.15 M, and 90 degreesC respectively. The effect of deposition potential on the structure of ZnTe films was investigated. The variations of the optical constants and dielectric constant of ZnTe thin films with wavelength were studied. The surface morphology and film composition were analysed by means of a scanning electron microscope and energy-dispersive x-ray analysis respectively. It is found that a minimum concentration of Zn2+ ions in the solution bath yielded stoichiometric films with smooth surfaces. Preliminary studies on photoelectrochemical solar cells based on ZnTe were carried out and the results are discussed.