Zhang Jianjun, Wang Linxi, Jiang Chenhui, Cheng Bei, Chen Tao, Yu Jiaguo
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, P. R. China.
Laboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, 430074, P. R. China.
Adv Sci (Weinh). 2021 Nov;8(21):e2102648. doi: 10.1002/advs.202102648. Epub 2021 Sep 13.
Organic-inorganic halide perovskite solar cells (PSCs) have drawn tremendous attention owing to their remarkable photovoltaic performance and simple preparation process. However, conventional wet-chemical synthesis methods inevitably create defects both in the bulk and at the interfaces of perovskites, leading to recombination of charge carriers and reduced stability. Herein, a bilateral interface modification to perovskites by doping room-temperature synthesized CsPbBr nanocrystals (CN) is reported. The ultrafast transient absorption measurement reveals that CN effectively suppresses the defect at the SnO /perovskite interface and boosts the interfacial electron transport. Meanwhile, the in situ Kelvin probe force microscopy and contact potential difference characterizations verify that the CN within the upper part of the perovskites enhances the built-in electric field, facilitating oriented migration of the carriers within the perovskite. Combining the superiorities of CN modifiers on both sides, the bilaterally modified CH NH PbI -based planar PSCs exhibit optimal power conversion efficiency exceeding 20% and improved device stability.
有机-无机卤化物钙钛矿太阳能电池（PSC）因其卓越的光伏性能和简单的制备工艺而备受关注。然而，传统的湿化学合成方法不可避免地会在钙钛矿的体相和界面处产生缺陷，导致电荷载流子复合并降低稳定性。在此，报道了一种通过掺杂室温合成的CsPbBr纳米晶体（CN）对钙钛矿进行双边界面修饰的方法。超快瞬态吸收测量表明，CN有效地抑制了SnO/钙钛矿界面处的缺陷，并促进了界面电子传输。同时，原位开尔文探针力显微镜和接触电势差表征证实，钙钛矿上部的CN增强了内建电场，有利于载流子在钙钛矿内的定向迁移。结合两侧CN改性剂的优势，双边修饰的基于CHNHPbI的平面PSC表现出超过20%的最佳功率转换效率和提高的器件稳定性。
