TiCl4-free 100.6 cm2 active area dye-sensitized solar cells with ∼8% power conversion efficiency

Abstract

The interface between fluorine-doped tin oxide (FTO) and mesoporous TiO2 plays a critical role in the power conversion efficiency (PCE) in dye-sensitized solar cells (DSCs). TiCl4 pretreatment has been proved to be effective to improve the electron collecting ability of FTO. However, pollution and danger have to be avoided in order to introduce such pretreatment into industrialized scale production of DSCs. This work explores an environmental-friendly, productive and effective way of FTO pretreatment, titanium-isopropoxide based solution together with spin coating process, to substitute TiCl4 pretreatment in DSCs fabrication. The PCE of the champion cell is remarkably improved from 5.35% to 7.98%, comparing to that of the cells fabricated with pristine FTO substrate. The method of spin coating titanium-isopropoxide based solution of FTO provides a productive and clean choice in scaling up production of DSCs for the application.