Electrodeposition of hierarchical ZnO nanorod-nanosheet structures and their applications in dye-sensitized solar cells.
Electrodeposition of hierarchical ZnO nanorod-nanosheet structures and their applications in dye-sensitized solar cells.
复制标题
DOI：
10.1021/am2002789
复制
发表时间：
2011-07
影响因子：
9.5
通讯作者：
Jianhang Qiu;Min Guo;Xidong Wang
中科院分区：
文献类型：
--
作者：
Jianhang Qiu;Min Guo;Xidong Wang
我们提出了一个两步电化学沉积过程来合成分级氧化锌（ZnO）纳米棒-纳米片结构的氧化铟锡（ITO）基板上，包括电沉积的ZnO纳米片阵列的导电玻璃基板上，然后通过电化学生长的第二次ZnO纳米棒的主要ZnO纳米片的骨干。讨论了分级纳米结构的形成机理。结果表明，退火处理的初级纳米片合成的第一步沉积过程中起着关键作用，在合成的分级纳米结构。研究了基于分级ZnO纳米结构的染料敏化太阳能电池（DSSC）的光伏特性。与使用裸ZnO纳米片阵列的光电极构造的DSSC相比，分级ZnO纳米棒-纳米片DSSC表现出改善的器件性能。这种改善可以归因于增强的染料负载，这是由纳米结构光电极内的内表面积的扩大引起的。此外，我们还进行了参数研究，通过调整第一步和第二步沉积工艺的制备条件来确定分级ZnO纳米棒-纳米片光电极的最佳几何尺寸。利用薄膜厚度约为7 μm的分级纳米结构光电极，成功地获得了开路电压为0.74 V，总功率转换效率为3.12%的DSSC。
We present a two-step electrochemical deposition process to synthesize hierarchical zinc oxide (ZnO) nanorod-nanosheet structures on indium tin oxide (ITO) substrate, which involves electrodeposition of ZnO nanosheet arrays on the conductive glass substrate, followed by electrochemical growth of secondary ZnO nanorods on the backbone of the primary ZnO nanosheets. The formation mechanism of the hierarchical nanostructure is discussed. It is demonstrated that annealing treatment of the primary nanosheets synthesized by the first-step deposition process plays a key role in synthesizing the hierarchical nanostructure. Photovoltaic properties of dye-sensitized solar cells (DSSCs) based on hierarchical ZnO nanostructures are investigated. The hierarchical ZnO nanorod-nanosheet DSSC exhibits improved device performance compared to the DSSC constructed using photoelectrode of bare ZnO nanosheet arrays. The improvement can be attributed to the enhanced dye loading, which is caused by the enlargement of internal surface area within the nanostructure photoelectrode. Furthermore, we perform a parametric study to determine the optimum geometric dimensions of the hierarchical ZnO nanorod-nanosheet photoelectrode through adjusting the preparation conditions of the first- and second-step deposition process. By utilizing a hierarchical nanostructure photoelectrode with film thickness of about 7 μm, the DSSC with an open-circuit voltage of 0.74 V and an overall power conversion efficiency of 3.12% is successfully obtained.