Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195, USA.
Nanoscale. 2013 Mar 7;5(5):1894-901. doi: 10.1039/c2nr33599a. Epub 2013 Jan 28.
In this paper, ZnO nanorod-nanosheet hierarchical structures were fabricated using a facile method on zinc foil and used as flexible photoanodes in dye-sensitized solar cells (DSCs). Compared to nanorods (NRs) obtained by the dissolution-precipitation method, the nanorod-nanosheet (NR-NS) hierarchical structures obtained by a second-step homogeneous precipitation improved the performance of DSCs by increasing photocurrent density significantly. As a result, the power conversion efficiency of the devices based on such a NR-NS hierarchical structure reached up to 2.4% under 100 mW cm(-2) illumination condition. This represents an enhancement by 108% as compared to DSCs based on NR assembled nanoflowers, for which the efficiency was 1.1%. The enhancement of the photocurrent was due mainly to the much larger specific surface area and resulting dye-loading amount. The electron transport properties in this structure were also investigated by means of electrochemical impedance spectroscopy (EIS). Furthermore, the formation mechanism of the NR-NS hierarchical structures are discussed.
本文采用简便的方法在锌箔上制备了 ZnO 纳米棒-纳米片分级结构，并将其用作染料敏化太阳能电池（DSC）中的柔性光阳极。与通过溶解-沉淀法获得的纳米棒（NRs）相比，通过第二步均匀沉淀获得的纳米棒-纳米片（NR-NS）分级结构通过显著提高光电流密度来提高 DSCs 的性能。结果，在 100 mW cm(-2)光照条件下，基于这种 NR-NS 分级结构的器件的功率转换效率达到了 2.4%。与基于 NR 组装纳米花的 DSCs 相比，效率为 1.1%，这提高了 108%。光电流的增强主要归因于更大的比表面积和由此增加的染料负载量。还通过电化学阻抗谱（EIS）研究了该结构中的电子传输特性。此外，讨论了 NR-NS 分级结构的形成机制。
