TiO2 films with rich bulk oxygen vacancies prepared by electrospinning for dye-sensitized solar cells

► Transparent TiO2 films were prepared by electrospinning. ► TiO2 films with rich bulk oxygen vacancies induce large Voc and FF in DSCs. ► We first used an unsensitized cell to investigate the trap-to-trap electron transport. ► The results from PL measurement show useful information.