二维微纳米结构表面反射特性的时域有限差分法模拟研究

亚波长微纳米结构表面具有优良的抗反射特性,本文以硅基太阳能电池响应光谱的300~1 200 nm为应用基础,利用时域有限差分法计算了表面面形、结构参量的占空比、高度和周期以及光波入射角等对二维微纳米结构表面反射特性的影响,并结合等效介质理论进行了进一步理论分析,结果表明:等截面光栅结构的反射率较大,结构参量影响也较小;锥形渐变截面光栅结构的抗反射性能较好,且反射率随着占空比、结构高度的增大而显著下降;同时,光波在光栅法线的±40°范围内入射时,反射率均较小.通过对亚波长微纳米光栅结构的反射特性的模拟和分析,为抗反射表面的设计和制作提供了基础.

Simulation and Research on Reflection Properties of Two-dimension Micro/nano Structure Surface by FDTD Method

The sub-wavelength micro/nano structure surfaces have an excellent anti-reflective property. Based on application foundation of silicon-based solar cells response spectrum of 300~1 200 nm, reflection characteristics of two-dimension micro/nano structure surface were calculated influenced by the surface face forms,structure parameters with duty ratio,height and period,and incident angle of light waves,using the finite difference time domain method.Further analysis was done by effective medium theory.The results show that the reflectivity is large for the grating structure of uniform section,and the influence of structure parameters is small; anti-reflective performance of a taped gradient section structure is much better,and the reflectivity is observably reduced with duty ratio and height increased; and it also showed that the reflectivity is a little smaller at the incident angle range of ±40°.The simulation and analysis on reflective property of sub-wavelength micro/nano grating structure,provide the basis on the design and fabrication of anti-reflection surfaces.