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Improved conversion efficiency of Ag2S quantum dot-sensitized solar cells based on TiO2 nanotubes with a ZnO recombination barrier layer

Chong Chen1, Yi Xie1, Ghafar Ali12, Seung Hwa Yoo1 and Sung Oh Cho1*

Author affiliations

1 Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong, Yuseong, Daejeon 305-701, Republic of Korea

2 Nanomaterials Research Group, Physics Division, PINSTECH, Islamabad, Pakistan

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Citation and License

Nanoscale Research Letters 2011, 6:462  doi:10.1186/1556-276X-6-462

Published: 21 July 2011


We improve the conversion efficiency of Ag2S quantum dot (QD)-sensitized TiO2 nanotube-array electrodes by chemically depositing ZnO recombination barrier layer on plain TiO2 nanotube-array electrodes. The optical properties, structural properties, compositional analysis, and photoelectrochemistry properties of prepared electrodes have been investigated. It is found that for the prepared electrodes, with increasing the cycles of Ag2S deposition, the photocurrent density and the conversion efficiency increase. In addition, as compared to the Ag2S QD-sensitized TiO2 nanotube-array electrode without the ZnO layers, the conversion efficiency of the electrode with the ZnO layers increases significantly due to the formation of efficient recombination layer between the TiO2 nanotube array and electrolyte.

quantum dots; TiO2 nanotube; Ag2S; solar cells