高等学校化学学报

高等学校化学学报 ›› 2006, Vol. 27 ›› Issue (3): 550.

• 研究快报 • 上一篇    下一篇

利用瞬态光电压技术对纳米TiO2 薄膜电极中光生电荷传输机理的研究

张清林,王德军,魏霄,肇启东,林艳红,杨敏   

  1. 吉林大学化学学院,长春 130023
  • 收稿日期:2005-09-23 出版日期:2006-03-10 发布日期:2006-03-10
  • 通讯作者: 王德军(1951年出生),男,教授,博士生导师,主要从事功能材料光化学与光物理研究. E-mail: wangdj@mail.jlu.edu.cn
  • 基金资助:

    国家自然科学基金(批准号: 20273027,20473033)、 吉林省科技发展基金(批准号: 20040503)和教育部博士学科点基金(批准号: 020183008)资助.

Studies on Tansport Mechanism of Photo-induced Charge Carrier on Nano-TiO2 Film Electrode Using Transient Photovoltage Technique

ZHANG Qing-Lin,WANG De-Jun*,WEI Xiao,ZHAO Qi-Dong,LIN Yan-Hong,YANG Min   

  1. College of Chemistry,Jilin University,Changchun 130023,China
  • Received:2005-09-23 Online:2006-03-10 Published:2006-03-10

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摘要：

利用瞬态光电压技术对光生电荷在纳米TiO2 薄膜电极中的传输机理进行了研究. 结果表明光生电荷在纳米TiO2薄膜的体相和TiO2/ITO界面分别以扩散和漂移进行分离传输的. 并且对光生电子在TiO2/ITO界面的俘获对光电压响应产生显著的影响. 这是由于在TiO2/ITO界面存在界面势垒,且带弯是从TiO2指向ITO向下弯曲. 同时也表明瞬态光电压是一种很好的表征光电功能材料的光电性质的方法.

关键词: 瞬态光电压; TiO2; 接触势垒; 光生电荷传输

Abstract:

Transient photovoltage(PV) technique was applied to investigate the separation and the transport mechanism of the photo-induced charge carriers on nano-TiO2 film electrode. The positive PV transients were observed whenever the light was incident from the gauze platinum(top illumination) or the ITO electrode(bottom illumination). This implies that the photo-induced electrons always accumulate near the ITO. Simultaneously,it is found that under the singe pulse illumination,PV transient at bottom illumination needs a shorter time to reach its maximum than that at top illumination. This indicates that the photo-induced carriers are separated faster on TiO2/ITO interface than that in the bulk of the TiO2 film. These demonstrate the existence of the contact potential on the TiO2/ITO interface,with the downward band bending from the TiO2 to ITO,which may cause the excess carriers to be separated by drift. Under the repeated pulses illumination,the PV transients at top illumination remained unchanged,while those at bottom illumination changed significantly. This results from the trapping of the excess electrons on the TiO2/ITO interface.

Key words: Transient photovoltage; TiO2; Contact potential; Transport of the photo-induced charge carrier

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