Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (06): 1240-1246.doi: 10.3866/PKU.WHXB201303261

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

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).


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