In this work, 3-Bromo-N-methylbenzylamine (3-B-N-MB) was designed to modify CsPbIBr/hole transport layer interface to reduce the interfacial non-radiative recombination loss of all-inorganic CsPbIBr perovskite solar cells (PSCs). The effects of 3-B-N-MB modification on the morphology, structure, optical absorption, defect concentration, carrier lifetime, energy level, hydrophobicity of CsPbIBr perovskite film and device performance, and carrier dynamics, as well as their mechanisms were systematically studied. The results show that the lone pair electrons in the N atom of N-H group in strongly alkaline 3-B-N-MB is more conducive to coordinate with uncoordinated Pb/Cs in CsPbIBr, meanwhile the H atom of N-H group in 3-B-N-MB can react with I/Br in CsPbIBr through hydrogen bonding, passivating interface defects to increase grain size and enhance the crystallinity and density of CsPbIBr films, optimizing interface energy level matching to promote carrier transport, thus suppressing interfacial non-radiative recombination to improve device performance. As a result, the PCE of the 3-B-N-MB modified PSCs significantly enhanced ∼32.5 % as compared to that of the pristine one and the air stability of the device has also improved. The 3-B-N-MB modification provides a new strategy to enhance the efficiency and stability of all-inorganic perovskite solar cells.

中文翻译：

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3-溴-N-甲基苄胺修饰对CsPbI2Br钙钛矿薄膜和钙钛矿太阳能电池的影响


在这项工作中，设计了3-溴-N-甲基苄胺（3-B-N-MB）来修饰CsPbIBr/空穴传输层界面，以减少全无机CsPbIBr钙钛矿太阳能电池（PSC）的界面非辐射复合损失。系统研究了3-B-N-MB修饰对CsPbIBr钙钛矿薄膜的形貌、结构、光吸收、缺陷浓度、载流子寿命、能级、疏水性和器件性能、载流子动力学的影响及其机制。结果表明，强碱性3-B-N-MB中N-H基团的N原子上的孤对电子更有利于与CsPbIBr中不配位的Pb/Cs配位，同时3-B-N-MB中N-H基团的H原子可以通过氢键与CsPbIBr中的I/Br发生反应，钝化界面缺陷，增大晶粒尺寸，增强CsPbIBr薄膜的结晶度和密度，优化界面能级匹配，促进载流子传输，从而抑制界面非辐射复合，提高器件性能。结果，3-B-N-MB 修饰的 PSC 的 PCE 与原始 PSC 相比显着提高了约 32.5%，并且器件的空气稳定性也得到了改善。 3-B-N-MB修饰为提高全无机钙钛矿太阳能电池的效率和稳定性提供了新策略。