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

Abstract 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 TiO 2 hybrid film on plastic substrate for flexible dye-sensitized solar cells (DSSCs) with quasi-solid state electrolyte, employing an inorganic binder contained TiO 2 paste. 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 cm 3  g −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 Al 2 O 3 layer on the TiO 2 surface 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.