Facile formation of a micro-crater structure for light scattering in quasi-solid state dye-sensitized solar cells
Herein, we introduce a hierarchical micro-porous TiO2 photo-anode with optimal morphology tailored for gel-type electrolyte DSSCs. To prepare a micro-crater structure, acetylene-black was blended into the TiO2 paste, and thereafter evaporated at high temperature in a sintering process. The formation of a micro-crater structure with optimal morphology improved the light scattering effect without an additional light scattering layer. In addition, it provided a wide entrance for a fast and complete electrolyte infiltration into the TiO2 film. Full contact between the TiO2 film and the gel-type electrolyte by the micro-crater structure improved the performance of the DSSCs compared to that of the DSSCs without a micro-crater structure. Photo-conversion efficiency of the DSSC using this method was enhanced from 7.9% to 8.7%, while maintaining a high stable efficiency in a 300 hours stability test.