Towards Improvement of Photovoltaic Performance of Aqueous Dye-sensitized Solar Cells by Tungsten-doped Mesoporous Nanobeads TiO₂ Working Electrode

Abstract

Tungsten doped (W-doped) TiO₂ mesoporous nanobeads, possessing high surface area and superior scattering effect, were used for photoanode preparation. The W-doping would induce a positive shift of the TiO₂ conduction band, and enhance the driving force for electron injection and collection efficiencies. The electrochemical impedance spectra indicated a retarded charge recombination and increased electron diffusion length after W-doping. By fine-tuning the W-doping concentration to 0.25%, aqueous DSCs produced a significant improved the open circuit voltage of 712 mV and a short circuit current of 7.05 mA·cm^-2, leading to an overall increased power conversion efficiency of 3.40% at 1 000 W·m^-2 simulated irradiation, which is roughly 25% enhancement compared to that without W-doping photoanode.

Keywords

tungsten-doping / dye-sensitized solar cells / aqueous electrolyte / conduction band