基于金属纳米球等离增强的高效钙钛矿/硅电池设计

Design of high efficiency perovskite/silicon tandem solar cells based on plasmonic enhancement of metal nanosphere

以钙钛矿为顶、晶硅为底的钙钛矿/硅叠层电池可以提高太阳光谱的利用率,突破单结电池中的肖克利极限(SQ极限),是实现更高光电转换效率的有效途径之一.如何降低光子在电池表面和界面的传输损失,最大化响应层的吸收效率是其中的关键.本文通过时域有限差分法和严格耦合波分析,系统研究了不同种类金属纳米球对钙钛矿/硅叠层电池的光谱响应和能量转换效率的增强机制.结果表明,由于表面电子云对光波的共振增强,金属纳米结构的引入显著提升了光子进入到电池响应层的透射率,电池总的吸收光谱和量子响应效率因而得到明显提升.对于最优的Al纳米球,观察到的加权平均透射率从73.16%提升到79.15%,电池能量转换效率从23.09%提高到24.97%,效率相对提高了8.14%.

Perovskite/silicon tandem solar cells,by combining perovskite as a top absorber material and crystalline silicon as a bottom absorber material,can expand and enhance the utilization of solar spectrum.Therefore,such a tandem structure shows great potential to break through the Shockley-Queisser(SQ)limit of 31%-33%for single-junction(SJ)solar cells and is considered as one of the most promising approaches to achieving the higher performance in photoelectric conversion of solar cells.Reducing the optical losses from the surface and interfaces of cell device and making more photons propagate into the active layers are the key factors for achieving the goal.In this paper,the enhancement of spectral response and energy conversion efficiency of perovskite/silicon tandem solar cells depending on Au,Ag,Cu,Al nanosphere are studied by using the finite difference time domain method and rigorous coupled-wave analysis.The results show that owing to the introduction of metal nanosphere,the transmittance of photons propagating into the active material is promoted significantly.Therefore,the cell device achieves an apparent increase both in total absorbance and in quantum efficiency.The observed weighted average transmittance and energy conversion efficiency are increased from 73.16%and 23.09%to 79.15%and 24.97%,respectively,with an 8.14%improvement for the perovskite/silicon tandem solar cells coated with the optimized Al nanospheres.