Flexible CdS photoelectrodes for photoelectrochemical solar cell applications

Nanocrystalline CdS thin films have been successfully deposited on mechanically flexible polyethylene terephthalate substrates via electrodeposition technique. Structural and optical properties of as-deposited and CuCl2 treated CdS thin films have been investigated using X-ray diffraction, UV-vis spectrophotometry and X-ray photoelectron spectroscopy. Both as-deposited and CuCl2-treated CdS samples have been integrated into photoelectrochemical solar cell. It has been observed that power conversion efficiency of thin films increased dramatically and reached approximately 2% after CuCl2-treatment. Electrochemical impedance spectroscopy has been used to investigate the charge transfer mechanism. Frequency dependent measurements indicated that it was possible to fit almost all as-deposited samples into one time constant model. On the other hand, mixed kinetic and diffusion model can be used to identify the charge transfer mechanism of CuCl2-treated samples.