物理化学学报 >> 2013, Vol. 29 >> Issue (06): 1240-1246.doi: 10.3866/PKU.WHXB201303261

电化学和新能源 上一篇    下一篇

CdSe/ZnS量子点敏化太阳能电池电子注入与光伏性能表征

郭旭东, 马蓓蓓, 王立铎, 高瑞, 董豪鹏, 邱勇   

  1. 清华大学化学系有机光电子及分子工程教育部重点实验室, 北京 100084
  • 收稿日期:2012-12-19 修回日期:2013-03-25 发布日期:2013-05-17
  • 通讯作者: 王立铎 E-mail:chldwang@mail.tsinghua.edu.cn
  • 基金资助:

    国家自然科学基金(51273104)和国家重点基础研究发展规划项目(973)(2009CB930602)资助

Electron Injection and Photovoltaic Properties in CdSe/ZnS Quantum Dot Sensitized Solar Cells

GUO Xu-Dong, Ma Bei-Bei, WANG Li-Duo, GAO Rui, DONG Hao-Peng, QIU Yong   

  1. Key Lab of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, China
  • Received:2012-12-19 Revised:2013-03-25 Published:2013-05-17
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51273104) and National Key Basic Research and Development Program of China (973) (2009CB930602).

摘要:

合成了CdSe/ZnS核壳结构量子点(QDs), 将其作为光敏剂吸附在TiO2纳米晶薄膜上, 组装成量子点敏化太阳能电池(QDSSCs), 从电子注入速率和电池性能两方面对QDSSCs进行了表征. 为了定量研究ZnS层包覆对电子注入的影响, 运用飞秒瞬态光谱技术, 测试了包覆ZnS前后, CdSe-TiO2体系的电子注入速率. 实验测得ZnS包覆前后电子注入速率分别为7.14×1011s-1和2.38×10-11s-1, 可以看出包覆后电子注入速率明显降低, 仅为包覆前的1/3. 电池器件J-V性能测试表明, ZnS作为绝缘层包覆在CdSe的表面有效提高了QDSSCs的填充因子和稳定性, 但同时也导致了效率的降低. 上述结果说明了电子注入速率的降低是导致电池电流和效率下降的重要原因, 为今后优化核壳结构QDSSCs的电流和效率提供了依据.

关键词: CdSe/ZnS量子点, ZnS包覆, 量子点敏化太阳能电池, 电子注入速率, 飞秒瞬态吸收光谱

Abstract:

CdSe/ZnS core/shell quantum dots (QDs) were synthesized and adsorbed onto nanocrystalline TiO2 films for application in quantum dot sensitized solar cells(QDSSCs). Femtosecond transient absorption spectra was measured to investigate the effect of the ZnS shell coating on electron injection from CdSe QDs to nanocrystalline TiO2 films. The results showed a decrease in electron injection rate from 7.14×1011s-1 to 2.38×10-11s-1 after ZnS shell coating, which means the electron injection rate only remained 1/3. The fill factor(FF) and stability of QDSSCs were improved by ZnS coating, but the photocurrent decreased, resulting in an overall decrease in efficiency. The slower electron injection rate is found to be the main cause for this decrease in photocurrent and efficiency, which matches well with the photovoltaic property test. These results provide information for optimizing the current and efficiency of QDSSCs employing core/shell QDs.

Key words: CdSe/ZnS quantum dots, ZnS coating, Quantum dot sensitized solar cell, Electron injection rate, Femtosecond transient absorption spectra

MSC2000: 

  • O649