Fmoc-FF-OH钝化钙钛矿薄膜及其太阳能电池性能研究

Perovskite Film Passivated by Fmoc-FF-OH and Its Photovoltaic Performance

有机-无机杂化钙钛矿具有高的光吸收系数、可调节的带隙以及双极性的电荷传导特性,是一种理想的光吸收材料。然而,溶液法制备的钙钛矿薄膜在表/界面上存在多种缺陷,会抑制载流子传输并引发复合。本研究选用含多官能团的氨基酸衍生物——9-芴甲氧羰基-L-苯丙氨酸-L-苯丙氨酸(Fmoc-FF-OH)作为添加剂来降低钙钛矿膜缺陷并抑制晶界上的载流子复合。结果表明,当Fmoc-FF-OH的浓度为0.6 g·L^(-1)时,钙钛矿薄膜的粒径从138 nm增大到210 nm,缺陷态密度从2.46×10^(15)cm^(-3)降低至2.17×10^(15)cm^(-3)。同时,钙钛矿太阳能电池也表现出最优的性能,开路电压从1.05 V提升到1.10 V,器件的光电转化效率(PCE)从15.50%提升到17.44%。在220 h的稳定性测试中,器件的光电转化效率仍能维持初始的71%。

Organic-inorganic hybrid perovskite is an ideal light absorption material due to its high light absorption coefficient,adjustable band gap and bipolar charge conduction characteristics.However,perovskite thin films prepared by solution method possess various defects in the surface and interface,which inhibit carrier transport and trigger recombination.In this study,a multifunctional amino acid derivative,9-fluorenylmethoxycarbonyl-L-phenylalanine-L-phenylalanine(Fmoc-FF-OH),was selected as an additive to reduce defects of perovskite film and to inhibit carrier recombination at grain boundaries.When the concentration of Fmoc-FF-OH is 0.6 g·L^(-1),the particle size of the perovskite thin film increases from 138 to 210 nm,and the defect state density decreases from 2.46×10^(15)to 2.17×10^(15)cm^(-3).Perovskite solar cells also exhibit optimal performance with open circuit voltage increasing from 1.05 to 1.10 V,and photoelectric conversion efficiency(PCE)improved from 15.50%to 17.44%.After stability test for 220 h,the photoelectric conversion efficiency of the device can still maintain 71%of the initial.