Flower‐like TiO2 with highly exposed {001} facets used as scattering layers for dye‐sensitized solar cells. Issue 4 (30th November 2015)

• Record Type: Journal Article
• Authors: Gan, Wei; Niu, Haihong; Shang, Xin; Zhou, Ru; Guo, Zhiqiang; Mao, Xiaoli; Wan, Lei; Xu, Jinzhang; Miao, Shiding
• Is Part Of: Physica status solidi. Volume 213:Issue 4(2016:Apr.)
• Page Start: 994
• Page End: 1001
• Publication Date: 2015-11-30
• Subjects: doped TiO2 -- dye‐sensitized solar cells -- facets -- fluorine -- photoanodes; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201532461
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : The TiO2 crystals of flower‐like shapes (FF‐TiO2 ) were prepared by a one‐step hydrothermal reaction from the metallic titanium powders. The synthesized TiO2 particles exhibit truncated tetragonal bipyramidal morphologies, which has ∼30% of the surface enclosed by the {001} facets. The FF‐TiO2 was employed as back‐illumination photoanodes in fabricating the dye‐sensitized solar cells (DSSCs). The power‐conversion efficiency of the DSSCs was found to increase from 5.35% to 7.65% after incorporation of the FF‐TiO2 into the P25 fabricated photoanodes. The specific structure and the dopant fluorine were proven to have great impacts on the lifetime ( τ n ) for the photoelectrons to stay in the conduction band of TiO2 and the recombination time ( τ r ) of the photogenerated electrons that would be quenched by the I3 − ions. Reasons for the improvement in the photovoltaic properties have been clarified as follows: (1) the microsized particles were prepared within the optimum size region for Mie scattering; (2) the flower‐shaped structured FF‐TiO2 enhanced the saturated capacity for adsorption of dye molecules; and (3) the {001} facets with adsorbed fluorine (F − ) at the surface could remove the trap states, and restrain the photoelectrons recombination between the photoanode and electrolyte.