基于光子晶体的高效太阳能电池反射器的研究

Design of Highly Efficient Reflector of Solar Cells Based on Photonic Crystal

设计了一种一维光子晶体的太阳能电池底部反射器,采用平面波展开法(PWM)计算禁带,得到当两个材料的介电常数差越大时,完全禁带越宽,对于Si/Air和Si/SiO2都在700～1 200 nm出现完全禁带,在此基础上利用勒让德多项式展开方法(LPEM)对该结构进行最优化,寻找到了高反射率时周期层数N,并考察了当入射角度不同时反射谱效率的问题,得出随着入射角度的增加,两种不同结构的一维光子晶体完全禁带均出现蓝移,证明了此种结构反射器具有高效的全方位反射性。把这种结构的背反射层用作太阳能电池的反射器可以大大提高电池的捕光能力,从而提高太阳能电池的的转化效率。

A one-dimensional photonic crystal is designed for solar reflector, using plane wave expansion method （PWM） to calculate band gap, finding that the greater difference of the dielectric constant between two materials, the wider of the complete band gap. For Si/Air and Si/SiO2, there are totally 700-1200nm band, based on this, using the Legendre polynomial expansion method （LPEM） to optimize the structure, find a period at the high reflectivity of layers N, examines the issue of the incident angle reflection spectrum efficiency, that coming with the incident angle increases, the two different structures of one-dimensional photonic band gap crystals are completely a blue shift, proved that such a reflector has efficient all-round reflectivity. The structure of the back-reflection layer for solar reflector can greatly improve the light-harvesting capacity of the battery, Thereby enhancing the conversion efficiency of solar cells.