The Optical-Electro-Chemical Properties of CdS/CdSe/ZnS Co-Sensitized TiO2 Solar Cells

Quantum dots solar cells (QDSSCs) based on the different CdS/CdSe/ZnS-TiO2 photo anodes were prepared by successive ionic layer adsorption and reaction (SILAR) processes. The CdS, CdSe and ZnS layers were considered by UV–Vis spectra for optical and the SILAR cycles of CdS, CdSe and ZnS show different impact on the performance of QDSSCs. With the deposition times of CdS increasing (from 1 to 5 cycles), the short circuit current density of the device is enhanced. On the contrary, the increasing deposition times of CdSe (from 1 to 5 cycles) has a negative effect for the generation and collection of photoelectron. In addition, the electrochemical impedance spectroscopy technology (EIS) was used to investigate the diffusion and recombination in QDSSCs. In addition, the dynamic resistances were discussed based on the EIS results.