CdS/CdSe co-sensitized SnO2 photoelectrodes for quantum dots sensitized solar cells

SnO 2 nanoparticles were synthesized by hydrothermal method and applied to photo-electrodes of quantum dots-sensitized solar cells (QDSSCs). After sensitizing SnO 2 films via CdS quantum dots , CdSe quantum dots was decorated on the surface of CdS/SnO 2 photo-electrodes to further improve the power conversion efficiency. CdS and CdSe quantum dots were deposited by successive ionic layer absorption and reaction method (SILAR) and chemical bath deposition method (CBD) respectively. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to identify the surface profile and crystal structure of SnO 2 photo-electrodes before and after deposited quantum dots. After CdSe co-sensitized process, an overall power conversion efficiency of 1.78% was obtained in CdSe/CdS/SnO 2 QDSSC, which showed 66.4% improvement than that of CdS/SnO 2 QDSSC.