Acta Chimica Sinica ›› 2013, Vol. 71 ›› Issue (08): 1149-1153.DOI: 10.6023/A13020196 Previous Articles     Next Articles



寇东星a,b, 刘伟庆a, 胡林华a, 陈双宏a, 黄阳a, 戴松元a   

  1. a 中国科学院新型薄膜太阳电池重点实验室 中科院等离子体物理研究所 合肥 230031;
    b 河南大学特种功能材料重点实验室 开封 475004
  • 投稿日期:2013-02-18 发布日期:2013-07-19
  • 通讯作者: 戴松元, E-mail:
  • 基金资助:

    项目受国家重点基础研究发展计划(No. 2011CBA00700)、国家高技术研究发展计划(No. 2011AA050527)、国家自然科学基金(Nos. 21003130, 21173228)、中国博士后科学基金(Nos. 20110490835, 2012T50581)资助.

Influence of O2 Annealed Electrode on Microcosmic Performances in Dye-sensitized Solar Cells

Kou Dongxinga,b, Liu Weiqinga, Hu Linhuaa, Chen Shuanghonga, Huang Yanga, Dai Songyuana   

  1. a Key Laboratory of Novel Thin Film Solar Cells, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031;
    b Key Laboratory For Special Functional Materials, Henan University, Kaifeng 475004
  • Received:2013-02-18 Published:2013-07-19
  • Supported by:

    Project supported by the National Basic Research Program of China (No. 2011CBA00700), the National High Technology Research and Development Program of China (No. 2011AA050527), the National Natural Science Foundation of China (Nos. 21003130, 21173228) and the China Postdoctoral Science Foundation (Nos. 20110490835, 2012T50581).

Over the last decade, different techniques had been employed to prepare nanoporous TiO2 electrode, aiming to improve the electron transport and depress electron recombination processes in dye-sensitized solar cells (DSCs). Preparing TiO2 films by various atmospheres and annealing processes was an effective method to change their surface properties. Many results had been published recently regarding the effect of annealing atmospheres on cell performances, but there is no detailed study disclosing the working mechanism of O2 annealed electrode so far. In the present work, the influence of O2 anneal electrode on charge transport and recombination processes in dye-sensitized solar cells (DSCs) was investigated. TiO2 films were prepared by a two-step annealing process. The 1st-step of annealing was performed in air or oxygen at 510℃ for 30 min which effectively removed the residual organics originated from the TiO2 precursor pastes. The 2nd-step of annealing was performed in nitrogen at 510℃ for 10 min which removed extra oxygen atoms resulted from the incorporation of oxygen atoms adsorbed onto photoanode surface during the 1st-step of annealing. Series resistance and fill factor (FF) of the cell can be improved by the 2nd-step. The surface properties of sintering films were characterized by X-ray photoelectron spectroscopy analysis (XPS). The microcosmic processes of recombination, transport and band edge movement were detected by intensity-modulated photocurrent spectroscopy (IMPS)/intensity-modulated photovoltage spectroscopy (IMVS). It was found that both open-circuit photovoltage (Voc) and short-circuit photocurrent (Jsc) were improved by O2 annealed electrode. O2 anneal could reduce the recombination centers of Ti3+ defects and the recombination between electron and was consequently depressed. Additionally, the electron transport process in TiO2 films was also improved due to the increase of dye absorption amount and more positive band shift by O2 anneal. Overall, O2 annealed electrode enhanced the light absorption efficiency, electron collection efficiency and injection efficiency, inducing the cell efficiency rose from 6.90% to 7.53%.

Key words: dye-sensitized, solar cells, anneal atmospheres, electron transport and recombination