Zhang Hao, Tu Cailing, Xue Chen, Wu Jianhong, Cao Yu, Zou Wei, Xu Wenjie, Wen Kaichuan, Zhang Ju, Chen Yu, Lai Jingya, Zhu Lin, Pan Kang, Xu Lei, Wei Yingqiang, Lin Hongzhen, Wang Nana, Huang Wei, Wang Jianpu
Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China.
Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China.
Nano Lett. 2021 May 12;21(9):3738-3744. doi: 10.1021/acs.nanolett.0c04900. Epub 2021 Apr 28.
Three-dimensional (3D) perovskites have been demonstrated as an effective strategy to achieve efficient light-emitting diodes (LEDs) at high brightness. However, most 3D perovskite LEDs still suffer from serious efficiency roll-off. Here, using FAPbI as a model system, we find that the main reason for efficiency droop and degradation in 3D perovskite LEDs is defects and the ion migration under electrical stress. By introducing bifunctional-molecule 3-chlorobenzylamine additive into the perovskite precursor solution, the detrimental effects can be significantly suppressed through the growth of high crystalline perovskites and defect passivation. This approach leads to bright near-infrared perovskite LEDs with a peak external quantum efficiency of 16.6%, which sustains 80% of its peak value at a high current density of 460 mA cm, corresponding to a high brightness of 300 W sr m. Moreover, the device exhibits a record half-lifetime of 49 h under a constant current density of 100 mA cm.
三维（3D）钙钛矿已被证明是实现高亮度高效发光二极管（LED）的有效策略。然而，大多数3D钙钛矿LED仍存在严重的效率滚降问题。在此，以FAPbI为模型体系，我们发现3D钙钛矿LED效率下降和退化的主要原因是缺陷以及电应力下的离子迁移。通过将双功能分子3-氯苄胺添加剂引入钙钛矿前驱体溶液中，可通过生长高结晶度的钙钛矿和缺陷钝化显著抑制有害影响。这种方法导致了明亮的近红外钙钛矿LED，其峰值外量子效率为16.6%，在460 mA cm的高电流密度下维持其峰值的80%，对应于300 W sr m的高亮度。此外，该器件在100 mA cm的恒定电流密度下表现出创纪录的49小时半衰期。
