Ko Yeong Hwan, Yu Jae Su
Department of Electronics and Radio Engineering, Kyung Hee University, Giheung-gu, Yongin, South Korea.
Opt Express. 2011 Jan 3;19(1):297-305. doi: 10.1364/OE.19.000297.
We study theoretically and experimentally the hemi-urchin shaped zinc oxide (ZnO) nanostructures for broadband and wide-angle antireflection coatings. The antireflective characteristics of hemi-urchin shaped ZnO nanostructures, which can be formed by integrating one-dimensional (1D) nanostructures (i.e., nanorods) on the periodic 2D structural architecture, are investigated. The optimization process is performed using a rigorous coupled-wave analysis method in terms of the order of taper of Si subwavelength gratings (SWGs) as a 2D structural architecture, the geometry of Si SWGs, and the height/size of ZnO nanorods. To simply test an experimental feasibility, a hemi-urchin shaped ZnO nanostructure is fabricated by hydrothermally growing ZnO nanorods on the periodic Si SWG structure. The angle-dependent reflectance of the hemi-urchin shaped ZnO nanostructures on the Si SWG is compared with that of the vertically aligned ZnO nanorod arrays on the Si substrate. The optimized hemi-urchin shaped ZnO nanostructure can significantly improve the antireflective property by suppressing the surface reflection over a broad spectrum and a wide range of angles of light incidence, indicating a reasonable agreement with the experimental results.
我们从理论和实验两方面研究了用于宽带和广角抗反射涂层的半海胆状氧化锌（ZnO）纳米结构。研究了通过在周期性二维结构体系上集成一维（1D）纳米结构（即纳米棒）形成的半海胆状ZnO纳米结构的抗反射特性。优化过程是使用严格耦合波分析方法，根据作为二维结构体系的硅亚波长光栅（SWG）的锥度顺序、硅SWG的几何形状以及ZnO纳米棒的高度/尺寸来进行的。为了简单测试实验可行性，通过在周期性硅SWG结构上水热生长ZnO纳米棒来制备半海胆状ZnO纳米结构。将硅SWG上半海胆状ZnO纳米结构的角度相关反射率与硅衬底上垂直排列的ZnO纳米棒阵列的反射率进行了比较。优化后的半海胆状ZnO纳米结构可以通过在宽光谱和宽入射角范围内抑制表面反射来显著提高抗反射性能，这与实验结果具有合理的一致性。
