Suppressing phase disproportionation in quasi-2D perovskite light-emitting diodes

作者：Kang Wang, Zih‐Yu Lin, Zihan Zhang, Linrui Jin, Ke Ma, Aidan H. Coffey, Harindi R. Atapattu, Yao Gao, Jee Yung Park, Zitang Wei, Blake P. Finkenauer, Chenhui Zhu, Xiangeng Meng, Sarah N. Chowdhury, Zhaoyang Chen, Tanguy Terlier, Thi‐Hoai Do, Yan Yao, Kenneth R. Graham, Alexandra Boltasseva, Tzung‐Fang Guo, Libai Huang, Hanwei Gao, Brett M. Savoie, Letian Dou · 发表于：Nature Communications · 年份：2023 · DOI：10.1038/s41467-023-36118-7 · 被引用次数：220 · 研究领域：Perovskite Materials and Applications、Organic Light-Emitting Diodes Research、2D Materials and Applications

Abstract Electroluminescence efficiencies and stabilities of quasi-two-dimensional halide perovskites are restricted by the formation of multiple-quantum-well structures with broad and uncontrollable phase distributions. Here, we report a ligand design strategy to substantially suppress diffusion-limited phase disproportionation, thereby enabling better phase control. We demonstrate that extending the π-conjugation length and increasing the cross-sectional area of the ligand enables perovskite thin films with dramatically suppressed ion transport, narrowed phase distributions, reduced defect densities, and enhanced radiative recombination efficiencies. Consequently, we achieved efficient and stable deep-red light-emitting diodes with a peak external quantum efficiency of 26.3% (average 22.9% among 70 devices and cross-checked) and a half-life of ~220 and 2.8 h under a constant current density of 0.1 and 12 mA/cm 2 , respectively. Our devices also exhibit wide wavelength tunability and improved spectral and phase stability compared with existing perovskite light-emitting diodes. These discoveries provide critical insights into the molecular design and crystallization kinetics of low-dimensional perovskite semiconductors for light-emitting devices.