Facile fabrication of highly porous photoanode at low temperature for all-plastic dye-sensitized solar cells with quasi-solid state electrolyte

Fabrication of stable plastic solar cells is interesting, but still remains a big challenge. In this study, we develop a facile technique to prepare highly porous TiO2hybrid film on plastic substrate for flexible dye-sensitized solar cells (DSSCs) with quasi-solid state electrolyte, employing an inorganic binder contained TiO2paste. Compared with a pristine P25 electrode, the obtained photoanode exhibits not only excellent mechanical stability but also improved charge transport property. Moreover, the semiconductor film also shows a highly porous structure with pore volume up to 0.25 cm3g-1, allowing unhindered infiltration of viscous quasi-solid state electrolyte. The obtained all-plastic DSSCs with quasi-solid state electrolyte demonstrate a high efficiency up to 3.6%, which is 76% higher than the devices based on pristine P25 electrodes. The cell efficiency can be further increased to 4.05% by depositing an insulating Al2O3layer on the TiO2surface to suppress electron recombination. The effects of the inorganic binder on the performance of the hybrid electrodes as well as the DSSCs are investigated by various techniques and measurements.