ZnO@TiO<sub>2</sub> Core/Shell Nanowire Arrays with Different Thickness of TiO<sub>2</sub> Shell for Dye-Sensitized Solar Cells
Liqing Liu,
Hui Wang,
Dehao Wang,
Yongtao Li,
Xuemin He,
Hongguang Zhang,
Jianping Shen
Affiliations
Liqing Liu
New Energy Technology Engineering Laboratory of Jiangsu Province & School of Science, Nanjing University of Posts and Telecommunications (NJUPT), Nanjing 210023, China
Hui Wang
New Energy Technology Engineering Laboratory of Jiangsu Province & School of Science, Nanjing University of Posts and Telecommunications (NJUPT), Nanjing 210023, China
Dehao Wang
College of Electronic and Optical Engineering, Nanjing University of Post and Telecommunications, Nanjing 210023, China
Yongtao Li
New Energy Technology Engineering Laboratory of Jiangsu Province & School of Science, Nanjing University of Posts and Telecommunications (NJUPT), Nanjing 210023, China
Xuemin He
New Energy Technology Engineering Laboratory of Jiangsu Province & School of Science, Nanjing University of Posts and Telecommunications (NJUPT), Nanjing 210023, China
Hongguang Zhang
New Energy Technology Engineering Laboratory of Jiangsu Province & School of Science, Nanjing University of Posts and Telecommunications (NJUPT), Nanjing 210023, China
Jianping Shen
College of Electronic and Optical Engineering, Nanjing University of Post and Telecommunications, Nanjing 210023, China
The ZnO@TiO2 core/shell nanowire arrays with different thicknesses of the TiO2 shell were synthesized, through depositing TiO2 on the ZnO nanowire arrays using the pulsed laser deposition process. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images show that these core/shell nanowires were homogeneously coated with TiO2 nanoparticles with high crystallinity, appearing to be a rather rough surface compared to pure ZnO nanowires. The efficiency of ZnO@TiO2 core/shell structure-based dye-sensitized solar cells (DSSCs) was improved compared with pure ZnO nanowires. This is mainly attributed to the enlarged internal surface area of the core/shell structures, which increases dye adsorption on the anode to improve the light harvest. In addition, the energy barrier which formed at the interface between ZnO and TiO2 promoted the charge separation and suppressed the carrier recombination. Furthermore, the efficiency of DSSCs was further improved by increasing the thickness of the TiO2 shell. This work shows an efficient method to achieve high power conversion efficiency in core/shell nanowire-based DSSCs.
