反式平面钙钛矿太阳电池的光学损失分析

Optical Loss Analysis of Inverted Planar Perovskite Solar Cells

实现高效率光伏器件的先决条件之一是入射光被吸光层有效吸收,因此系统分析钙钛矿光伏电池中的光学损失机制,优化吸光层的光吸收,对于提升效率十分重要。本文针对反式平面钙钛矿太阳电池,结合电池外量子效率(EQE)、薄膜光吸收特性和理论模拟,对比研究钙钛矿吸光层和[6,6]-phenyl-C61-butyric acid methyl ester(PCBM)界面层厚度变化对光生电流的影响。研究结果显示,除了寄生吸收以外,界面层对光场的调节可以影响器件中吸光层的光吸收。模拟结果显示,660 nm的钙钛矿薄膜和40 nm的PCBM薄膜可作为优化的选择,其对应积分电流为24.93 mA/cm^(2)。本文还探究了PbI_(2)层的加入对钙钛矿吸光层吸收特性的影响,结果显示PbI_(2)聚集在钙钛矿层靠入射光侧时会导致显著的光学损失,而PbI_(2)聚集在钙钛矿层靠背电极一侧时,则影响相对较小。

One of the prerequisites for realizing high efficiency photovoltaic devices is that the incident light is effectively absorbed by the light absorbing layer.Therefore,it is very important to improve efficiency to systematically analyze the optical loss mechanism of perovskite photovoltaic cells and optimize the light absorption of the light absorbent layer.In this paper,for inverted planar perovskite solar cells,combining with the external quantum efficiency(EQE)of the cell,the light absorption characteristics of the film and theoretical simulation,the effects of the thickness changes of perovskite thin film as the light absorption layer and[6,6]-phenyl-C61-butyric acid methyl ester(PCBM)thin film as the interface layer on photogenerated current were compared and studied.The results show that,in addition to parasitic absorption,the adjustment of the optical field by the interface layer can affect the optical absorption of the light absorption layer in the device.The simulation results show that 660 nm perovskite film and 40 nm PCBM film can be used as the optimal choice,and the corresponding integral current is 24.93 mA/cm^(2).This paper also explored the influence of the addition of PbI_(2) layer on the absorption characteristics of the perovskite light absorbing layer.The results indicate that when PbI_(2) accumulates on the side of the perovskite layer near the incident light,it leads to significant optical loss.However,when PbI_(2) accumulates on the side of the perovskite layer near the back electrode,the influence is relatively small.