(623c) CdS Sensitized Nanostructured TiO2 and ZnO Solar Cells

A disadvantage of using organic dye in current dye sensitized solar cell technology is that it can rapidly deteriorate under the illumination of UV light. This instability can possibly be overcome by using quantum dots or nano-sized particles of CdS as an alternative sensitizer. The effects of post annealing treatment were investigated on the CdS sensitized ZnO and TiO2 nanocrystalline solar cells. It was found that the annealing will increase the cell efficiency on ZnO and TiO2 with porous structures. A significant increase of cell efficiency from 0.54% to 1.07% was observed for CdS sensitized porous ZnO solar cells after annealing and 0.52% to 1.29% for CdS sensitized electrospun porous TiO2 electrode. The increase is attributed to the film morphology improvement and the absorption band edge shift of CdS. The annealing does not increase the efficiency for solar cells made from CdS sensitized TiO2 without porous structure.