前界面缺陷对钙钛矿太阳电池性能的影响模拟

通过对光伏器件的模拟分析可以进一步提高对器件的认识深度,在实际工艺中利于优化器件制备条件,为高效钙钛矿太阳电池提供新思路.借助SCAPS模拟软件研究钙钛矿电池中钙钛矿吸收层、CH_3NH_3PbI_(3-x)Cl_x/TiO_2界面、TCO/TiO_2界面中缺陷态密度对电池性能的影响,模拟表明CH_3NH_3P I_(3-x)Cl_x中缺陷态密度和缺陷能级位置对器件效率的影响非常大,当缺陷态密度小于10~(16)cm~(-3)时,器件光电转换效率都能保持较高数值,达到16%以上.CH_3NH_3PbI_(3-x)Cl_x/TiO_2界面层中CH_3NH_3PbI_(3-x)Cl_x缺陷态密度对器件的FF影响较大,当缺陷态密度小于10~(17)cm~(-3)时器件填充因子都能保持较高的数值,达到78%以上.TiO_2缺陷态密度降低和掺杂浓度提高对器件填充因子和开路电压都有利.TCO/TiO_2界面层中适当增大窗口层掺杂浓度和带隙可以有效改善器件的光伏性能.

Simulation Study on the Effect of Front Interface Defects on the Performance of Perovskite Solar Cells

The simulation analysis of the photovoltaic device can help researchers to further understand the device characteristics, which can be benefit to optimize the device preparation conditions in the actual process, leading to high efficient perovskite solar cells. In this paper, SCAPS simulation software was used to study the effect of defect density including perovskite absorption layer, CH3NH3PbI3-xClx/TiO2 interface and TCO/TiO2 interface on the performance in perovskite devices. The simulation results showed that the defect density and defect level position in CH3NH3PbI3-xClx had a great effect on the efficiency of the device. When the defect density was less than 1016 cm-3, the photoelectric conversion efficiency of the device could be achieved a high value, more than 16%. The defect density of CH3NH3PbI3-xClx in CH3NH3PbI3-xClx/TiO2 interface layer had a great effect on the fill factor of the device. When the defect density was less than 1017 cm-3, the fill factor can maintain 78% or more. The decrease of TiO2 defect density and increase of doping concentration were beneficial to fill factor and open circuit voltage. The appropriate doping concentration and band gap for transparent conductive oxide (TCO) in TCO/TiO2 interface layer can effectively enhance the photovoltaic performance of the devices.