40% enhanced photocurrent of dye sensitized solar cells using lotus-shaped H2-treated anatase TiO2 with {0 0 1} dominated facets

Abstract After hydrogen treatment, lotus-shaped nitrogen and fluorine co-modified anatase TiO 2 (NF-TiO 2 ) with {0 0 1} facets have been synthesized and employed as photoanode materials in dye sensitized solar cells (DSSCs). In comparison with non-modified TiO 2 based DSSC, we obtain a 40% enhancement of photocurrent and a 38% increase of photoelectric conversion efficiency. UV–visible absorption spectroscopy (UV–vis) and Mott-Schottky plots combined with valence band analysis are used to characterize the electronic structure variation and study the synergistic effect of hydrogen treatment. The result shows an enhanced light absorbing ability, is a positively shifted flat band potential and an increased donor density. These improvements can be mainly ascribed to the appropriate electronic structure and the effective light-scattering centers. This work provides systematic and comprehensive research on the application of hydrogenation and {0 0 1} facets dominated nitrogen and fluorine co-modified TiO 2 in DSSC, and the hydrogenation treatment can lead to improved charge transport and recombination, enhanced light absorbing ability as well as elevated donor density of semiconductor. With these merits, {0 0 1} facets dominated HNF-TiO 2 nanopowders in this work may find its way in enormous energy and photoelectric fields.