Qin Jiajun, Zhang Jia, Liu Xianjie, Wang Yu, Wang Heyong, Singh Utkarsh, Wang Yanyan, Wang Haoliang, Hu Tianxiang, Zhan Yiqiang, Tang Yipeng, Hu Bin, Bach Constantin, Deibel Carsten, Ni Wei-Xin, Simak Sergei I, Abrikosov Igor A, Fahlman Mats, Gao Feng
Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden.
The State Key Laboratory of Photovoltaic Science and Technology, Shanghai Frontiers Science Research Base of Intelligent Optoelectronics and Perception, Institute of Optoelectronics, Fudan University, Shanghai, P. R. China.
Nat Mater. 2025 May;24(5):778-784. doi: 10.1038/s41563-025-02123-y. Epub 2025 Mar 5.
It is widely acknowledged that constructing small injection barriers for balanced electron and hole injections is essential for light-emitting diodes (LEDs). However, in highly efficient LEDs based on metal halide perovskites, a seemingly large hole injection barrier is usually observed. Here we rationalize this high efficiency through a surfactant-induced effect where the hole concentration at the perovskite surface is enhanced to enable sufficient bimolecular recombination pathways with injected electrons. This effect originates from the additive engineering and is verified by a series of optical and electrical measurements. In addition, surfactant additives that induce an increased hole concentration also significantly improve the luminescence yield, an important parameter for the efficient operation of perovskite LEDs. Our results not only provide rational design rules to fabricate high-efficiency perovskite LEDs but also present new insights to benefit the design of other perovskite optoelectronic devices.
人们普遍认为，构建用于平衡电子和空穴注入的小注入势垒对于发光二极管（LED）至关重要。然而，在基于金属卤化物钙钛矿的高效LED中，通常会观察到一个看似很大的空穴注入势垒。在此，我们通过表面活性剂诱导效应来解释这种高效率，即钙钛矿表面的空穴浓度得以提高，从而能够与注入的电子形成足够的双分子复合路径。这种效应源于添加剂工程，并通过一系列光学和电学测量得到验证。此外，诱导空穴浓度增加的表面活性剂添加剂还显著提高了发光产率，这是钙钛矿LED高效运行的一个重要参数。我们的结果不仅为制造高效钙钛矿LED提供了合理的设计规则，也为其他钙钛矿光电器件的设计带来了新的见解。
