Jung Jin-Young, Guo Zhongyi, Jee Sang-Won, Um Han-Don, Park Kwang-Tae, Lee Jung-Ho
Department of Chemical Engineering, Hanyang University, Ansan, Kyounggi, Korea.
Opt Express. 2010 Sep 13;18 Suppl 3:A286-92. doi: 10.1364/OE.18.00A286.
Vertically aligned silicon nanowires (SiNWs) were cost-effectively formed on a four-inch silicon wafer using a simple room temperature approach, i.e., metal-assisted electroless etching. Tapering the NWs by post-KOH dipping achieved separation of each NW from the bunched NW, resulting in a strong enhancement of broadband optical absorption. As electroless etching time increases, the optical crossover feature was observed in the tradeoff between enhanced light trapping (by graded-refractive index during initial tapering) and deteriorated reflectance (by decreasing the areal density of NWs during later tapering). Compared to the bunched SiNWs, tapered NW solar cells demonstrated superior photovoltaic characteristics, such as a short circuit current of 17.67 mA/cm² and a cell conversion efficiency of ~6.56% under 1.5 AM illumination.
采用一种简单的室温方法，即金属辅助化学蚀刻，在四英寸硅片上经济高效地形成了垂直排列的硅纳米线（SiNWs）。通过KOH后浸渍使纳米线变细，实现了每根纳米线与成束纳米线的分离，从而显著增强了宽带光吸收。随着化学蚀刻时间的增加，在增强光捕获（通过初始变细过程中的渐变折射率）和反射率恶化（通过后期变细过程中纳米线面密度的降低）之间的权衡中观察到了光学交叉特征。与成束的SiNWs相比，锥形纳米线太阳能电池表现出优异的光伏特性，例如在1.5 AM光照下短路电流为17.67 mA/cm²，电池转换效率约为6.56%。
