Wang Jingwei, Shi Run, Wang Weijun, Cai Nianduo, Chen Pengcheng, Kong Dejun, Amini Abbas, Cheng Chun
Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China.
Center for Infrastructure Engineering, Western Sydney University, Kingswood, New South Wales, 2751, Australia.
Sci Rep. 2018 Aug 16;8(1):12283. doi: 10.1038/s41598-018-29652-8.
Hierarchical nanostructures are ideal architectures to harvest solar energy. The understanding of light absorption in single hierarchical structures is emergently important and greatly helpful in enhancing multiscale optical phenomena and light management. However, due to the geometrical complexity of hierarchical architectures, theoretical and experimental studies of light absorption have faced significant challenges. Here, we directly quantify light absorption in single hierarchical structures for the first time by utilizing VO-based near field powermeter. It is found that light trapping is significantly enhanced in rough microwires when the roughness amplitude is comparable to the incident light wavelength. The roughness enhanced light absorption is verified as a general phenomenon on both VO and Si hierarchical structures. Therefore, our work not only provides a simple and quantitative method of measuring light absorption upon single geometrically complex structures in micro/nanoscale, but also contributes a general rule to rationally design of hierarchical structures for enhanced performance in photoelectric and photochemical applications.
分级纳米结构是收集太阳能的理想架构。理解单个分级结构中的光吸收至关重要，对于增强多尺度光学现象和光管理有极大帮助。然而，由于分级架构的几何复杂性，光吸收的理论和实验研究面临重大挑战。在此，我们首次利用基于VO的近场功率计直接量化单个分级结构中的光吸收。研究发现，当粗糙度幅度与入射光波长可比时，粗糙微线中的光捕获显著增强。粗糙度增强光吸收在VO和Si分级结构上均被证实为普遍现象。因此，我们的工作不仅提供了一种简单且定量的方法来测量微/纳米尺度下单个几何复杂结构的光吸收，还为合理设计分级结构以提高光电和光化学应用性能贡献了一条通用规则。
