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Nano Research

, Volume 10, Issue 11, pp 3671–3679 | Cite as

Surface states in TiO2 submicrosphere films and their effect on electron transport

  • Jiawei Zheng
  • Li’e Mo
  • Wangchao Chen
  • Ling Jiang
  • Yong Ding
  • Zhaoqian Li
  • Linhua HuEmail author
  • Songyuan DaiEmail author
Research Article

Abstract

Owing to their special three-dimensional network structure and high specific surface area, TiO2 submicrospheres have been widely used as electron conductors in photoanodes for solar cells. In recent years, utilization of TiO2 submicrospheres in solar cells has greatly boosted the photovoltaic performance. Inevitably, however, numerous surface states in the TiO2 network affect electron transport. In this work, the surface states in TiO2 submicrospheres were thoroughly investigated by charge extraction methods, and the results were confirmed by the cyclic voltammetry method. The results showed that ammonia can effectively reduce the number of surface states in TiO2 submicrospheres. Furthermore, in-depth characterizations indicate that ammonia shifts the conduction band toward a more positive potential and improves the interfacial charge transfer. Moreover, charge recombination is effectively prevented. Overall, the cell performance is essentially dependent on the effect of the surface states, which affects the electron transfer and recombination process.

Keywords

surface states TiO2 submicrospheres solar cells charge extraction methods cyclic voltammetry 

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Notes

Acknowledgements

This work was supported by the National High-tech R&D Program of China (No. 2015AA050602), the External Cooperation Program of BIC, Chinese Academy of Sciences (No. GJHZ1607), the National Natural Science Foundation of China (Nos. U1205112, 51572080 and 21273242) and Natural Science Foundation of Anhui Province (No. 1508085SMF224).

Supplementary material

12274_2017_1577_MOESM1_ESM.pdf (1.5 mb)
Surface states in TiO2 submicrosphere films and their effect on electron transport

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Copyright information

© Tsinghua University Press and Springer-Verlag GmbH Germany 2017

Authors and Affiliations

  • Jiawei Zheng
    • 1
    • 2
  • Li’e Mo
    • 1
  • Wangchao Chen
    • 1
  • Ling Jiang
    • 1
  • Yong Ding
    • 3
    • 1
  • Zhaoqian Li
    • 1
  • Linhua Hu
    • 1
    Email author
  • Songyuan Dai
    • 3
    • 1
    Email author
  1. 1.Key Laboratory of Novel Thin Film Solar Cells, Institute of Applied Technology, Hefei Institutes of Physical ScienceChinese Academy of SciencesHefeiChina
  2. 2.University of Science and Technology of ChinaHefeiChina
  3. 3.Beijing Key Laboratory of Novel Thin Film Solar CellsNorth China Electric Power UniversityBeijingChina

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