Hydrothermal Growth and Application of ZnO Nanowire Films with ZnO and TiO2Buffer Layers in Dye-Sensitized Solar Cells

Weiguang Yang,Farong Wan,Chunhua Jiang,Siwei Chen

doi:10.1007/s11671-009-9425-4

Weiguang Yang, Farong Wan + Show 2 more

Open Access

https://doi.org/10.1007/s11671-009-9425-4

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Abstract

This paper reports the effects of the seed layers prepared by spin-coating and dip-coating methods on the morphology and density of ZnO nanowire arrays, thus on the performance of ZnO nanowire-based dye-sensitized solar cells (DSSCs). The nanowire films with the thick ZnO buffer layer (~0.8–1 μm thick) can improve the open circuit voltage of the DSSCs through suppressing carrier recombination, however, and cause the decrease of dye loading absorbed on ZnO nanowires. In order to further investigate the effect of TiO2buffer layer on the performance of ZnO nanowire-based DSSCs, compared with the ZnO nanowire-based DSSCs without a compact TiO2buffer layer, the photovoltaic conversion efficiency and open circuit voltage of the ZnO DSSCs with the compact TiO2layer (~50 nm thick) were improved by 3.9–12.5 and 2.4–41.7%, respectively. This can be attributed to the introduction of the compact TiO2layer prepared by sputtering method, which effectively suppressed carrier recombination occurring across both the film–electrolyte interface and the substrate–electrolyte interface.

Highlights

Dye-sensitized solar cells (DSSCs) based on a dye-sensitized wide-band-gap nanocrystalline semiconductor film have attracted widespread attention as a potential, cost-effective alternative to silicon solar cells since they were first introduced by O’Regan and Gratzel in 1991 [1]
We show that carrier recombination in ZnO nanowire-based dye-sensitized solar cells can be effectively suppressed and the photovoltaic conversion efficiency enhanced by introducing the TiO2 buffer layer prepared by sputtering method
We found that the different ZnO seed preparation methods strongly influenced the morphology and density of ZnO nanowire arrays, leading to the different performance of the DSSCs based on the ZnO nanowire films

Summary

Introduction

Dye-sensitized solar cells (DSSCs) based on a dye-sensitized wide-band-gap nanocrystalline semiconductor (typically TiO2) film have attracted widespread attention as a potential, cost-effective alternative to silicon solar cells since they were first introduced by O’Regan and Gratzel in 1991 [1]. We show that carrier recombination in ZnO nanowire-based dye-sensitized solar cells can be effectively suppressed and the photovoltaic conversion efficiency enhanced by introducing the TiO2 buffer layer prepared by sputtering method.

Results

Conclusion