一种选择性增强光谱吸收比／发射率的薄膜结构  

A LAYERED STRUCTURE OF THIN FILMS FOR SELECTIVELY IMPROVED ABSORPTIVITY/EMISSIVITY OF THERMAL RADIATION

作　　者：符策基[1] 谭文长[1] 

机构地区：[1]北京大学湍流与复杂系统国家重点实验室及力学与空天技术系,北京100871

出　　处：《工程热物理学报》2009年第2期285-287,共3页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No．50606001)

摘　　要：本文利用严格耦合波分析(RCWA)的方法数值求解并分析了一个半导体硅和金属银组成的复合薄膜结构,该结构的界面处具有一维周期性的微槽结构。结果显示,微槽结构的存在大大增强了该复合薄膜结构在硅能隙对应波长附近的光谱吸收比/发射率,而在波长大于能隙波长区域仍然保持较低吸收比/发射率。增强原因是由于界面处的电磁表面波(electromagnetic surface wave)被激发以及微槽多阶衍射波的相互作用的结果。通过调整微槽的几何尺寸可对该复合薄膜结构的吸收比/发射率进行优化。这种结构在光电能量转换系统中有潜在用处。Using the rigorous coupled-wave analysis algorithm, the absorptivity/emissivity of a layered structure composed of Si and Ag with a 1-D grating formed at the interface was numerically analyzed. The numerical results show that the layered structure exhibits enhanced spectral absorptivity/emissivity for photon energy slightly above the gap energy of Si. The enhancement is explained as due to excitations of electromagnetic surface waves in the grating region, along with interactions of multiple-order diffracted waves in the Si layer. Optimized enhancement can be obtained by tuning the grating geometry so that it may have potential applications in photovoltaic energy conversion purposes.

关 键 词：严格耦合波分析 热辐射 薄膜结构 电磁表面波 

分 类 号：TK124[动力工程及工程热物理—工程热物理]