Structural and photoeletrochemical properties of Cd_1-xZn_xS thin films

Cd_1-xZn_xS thin films were prepared on ITO conductive glass by ultrasonic spray pyrolysis. Some properties of the deposited film, such as structure, morphology and optical characteristics, were characterized by XRD, SEM, and UV-vis spectrum. And the photocurrent action spectrum was investigated via lock-in technique. It is found that high crystallinity and uniform Cd_1-xZn_xS film fine adhesion to ITO substrate can be prepared by ultrasonic spray pyrolysis. XRD patterns show that CdS exhibits a Hexagonal structure, and the crystals obtained are not a mixture of ZnS and CdS, but Cd_1-xZn_xS solid solution. The band gap of Cd_1-xZn_xS linearly increase with increasing Zn content. As a photoanode, the deposited film exhibits a good photoresponse. In 0.1 mol/L Na₂SO₃ and 0.1 mol/L Na₂S mixed solution, CdS shows the highest IPCE which achieves over 20% at a potential of 0.3 V vs. SCE(Saturated Calomel Electrode) at 420 nm irradiation wavelength.