Department of Mechanical Engineering, KAIST (Korea Advanced Institute of Science and Technology), Yuseong-gu, Korea.
Nano Lett. 2011 Feb 9;11(2):666-71. doi: 10.1021/nl1037962. Epub 2011 Jan 5.
In this paper, in order to increase the power conversion efficiency we demonstrated the selective growth of "nanoforest" composed of high density, long branched "treelike" multigeneration hierarchical ZnO nanowire photoanodes. The overall light-conversion efficiency of the branched ZnO nanowire DSSCs was almost 5 times higher than the efficiency of DSSCs constructed by upstanding ZnO nanowires. The efficiency increase is due to greatly enhanced surface area for higher dye loading and light harvesting, and also due to reduced charge recombination by providing direct conduction pathways along the crystalline ZnO "nanotree" multi generation branches. We performed a parametric study to determine optimum hierarchical ZnO nanowire photoanodes through the combination of both length-wise growth and branched growth processes. The novel selective hierarchical growth approach represents a low cost, all solution processed hydrothermal method that yields complex hierarchical ZnO nanowire photoanodes by utilizing a simple engineering of seed particles and capping polymer.
在本文中，为了提高功率转换效率，我们展示了由高密度、长分支“树状”多代分层 ZnO 纳米线光电阳极组成的“纳米林”的选择性生长。分支 ZnO 纳米线 DSSC 的整体光转换效率几乎比由直立 ZnO 纳米线构建的 DSSC 的效率高 5 倍。效率的提高是由于更高的染料负载和光捕获的表面积大大增加，并且由于沿着结晶 ZnO“纳米树”多代分支提供直接传导途径，减少了电荷复合。我们通过结合纵向生长和分支生长过程进行了参数研究，以确定最佳的分层 ZnO 纳米线光电阳极。这种新颖的选择性分层生长方法代表了一种低成本、全溶液处理的水热方法，通过利用简单的种子颗粒和盖帽聚合物的工程设计，得到复杂的分层 ZnO 纳米线光电阳极。
