Enhanced electron injection/transportation by surface states increment in mesoporous TiO₂ dye-sensitized solar cells

Abstract

A strategy of surface modification to the mesoporous TiO₂ photoanode with hydrochloric acid treatment was used in this study, and it was found that short circuit current and photovoltaic efficiency of dye-sensitized solar cells (DSSCs) were increased by 5.5% and 8.9% respectively. The improvement was attributed to the reduced impedances in the TiO₂ film and at the TiO₂/dye/electrolyte interface. It was showed that the increased surface electronic states could remarkably prolong electron lifetime, which was responsible for the reduction of impedances. Under these quasi-continuous states in mesoporous structure, the electron injection/transportation can be notably facilitated, which will be beneficial for the DSSC performance.

Keywords

dye-sensitized solar cell (DSSC) / surface states / surface modification / electron transportation

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Acknowledgements

This work was support by the National Natural Science Foundation of China (Grant Nos. 20725311, 20673141, 20703063, 20873178, and 20721140647), the Major State Basic Research Development Program of China (No. 2006CB202606), the National High Technology Research and Development Program of China (No. 2006AA03Z341), and the 100-Talents Project of Chinese Academy of Sciences and Foundation of the Chinese Academy of Sciences (Nos. KJCX2-YW-W27, KGCX2-YW-386-1, and KGCX2-YW-363).

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