title: High Efficiency Dye-sensitized Solar Cells Constructed with Composites of TiO2 and the Hot-bubbling Synthesized Ultra-Small SnO2 Nanocrystals.
abstract: An efficient photo-anode for the dye-sensitized solar cells (DSSCs) should have features of high loading of dye molecules, favorable band alignments and good efficiency in electron transport. Herein, the 3.4 nm-sized SnO2 nanocrystals (NCs) of high crystallinity, synthesized via the hot-bubbling method, were incorporated with the commercial TiO2 (P25) particles to fabricate the photo-anodes. The optimal percentage of the doped SnO2 NCs was found at ~7.5% (SnO2/TiO2, w/w), and the fabricated DSSC delivers a power conversion efficiency up to 6.7%, which is 1.52 times of the P25 based DSSCs. The ultra-small SnO2 NCs offer three benefits, (1) the incorporation of SnO2 NCs enlarges surface areas of the photo-anode films, and higher dye-loading amounts were achieved; (2) the high charge mobility provided by SnO2 was confirmed to accelerate the electron transport, and the photo-electron recombination was suppressed by the highly-crystallized NCs; (3) the conduction band minimum (CBM) of the SnO2 NCs was uplifted due to the quantum size effects, and this was found to alleviate the decrement in the open-circuit voltage. This work highlights great contributions of the SnO2 NCs to the improvement of the photovoltaic performances in the DSSCs.
authors.affiliation: School of Electronic Science and Applied Physics, Hefei University of Technology (HFUT), Hefei 230009, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Mao
authors.affiliation: School of Electronic Science and Applied Physics, Hefei University of Technology (HFUT), Hefei 230009, China.
authors.forename: Ru
authors.initials: R
authors.lastname: Zhou
authors.affiliation: School of Electronic Science and Applied Physics, Hefei University of Technology (HFUT), Hefei 230009, China.
authors.forename: Shouwei
authors.initials: S
authors.lastname: Zhang
authors.affiliation: School of Chemistry and Chemical Engineering, HFUT, Hefei, 230009, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Ding
authors.affiliation: School of Electronic Science and Applied Physics, Hefei University of Technology (HFUT), Hefei 230009, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wan
authors.affiliation: School of Electronic Science and Applied Physics, Hefei University of Technology (HFUT), Hefei 230009, China.
authors.forename: Shengxian
authors.initials: S
authors.lastname: Qin
authors.affiliation: Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie (IMPMC), Sorbonne Universités-UPMC Univ. Paris 06, Paris 75005, France.
authors.forename: Zhesheng
authors.initials: Z
authors.lastname: Chen
authors.affiliation: School of Electronic Science and Applied Physics, Hefei University of Technology (HFUT), Hefei 230009, China.
authors.forename: Jinzhang
authors.initials: J
authors.lastname: Xu
authors.affiliation: School of Chemistry and Chemical Engineering, HFUT, Hefei, 230009, China.
authors.forename: Shiding
authors.initials: S
authors.lastname: Miao