Stable Perovskite Quantum Dots Light‐Emitting Diodes with Efficiency Exceeding 24

• Published in: Advanced science 2023-12, Vol.10 (36), p.e2304696-n/a
• Main Authors: Zhang, Xuanyu, Wang, Qiangqiang, Yao, Zhiwei, Deng, Ming, Wang, Jing, Qian, Lei, Ren, Yong, Yan, Yuying, Xiang, Chaoyu
• Format: Article
• Language: English
• Subjects: Acids; Efficiency; Equilibrium; Humidity; LEDs; Ligands; Light emitting diodes; Nanocrystals; narrow emission; perovskite nanocrystals; Quantum dots; stability; Surfactants; synthesis
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202304696

Perovskite nanocrystals for light‐emitting diodes are often synthesized by uncontrollable metathesis reactions, suffering from low product yield, nonuniform growth, and poor stability. Herein, by controlling the nucleation kinetics with high dissociation constant (Ka or Kb) acids or bases, homogenous one‐route nucleation of perovskite nanocrystals is achieved as the cluster intermediates are eliminated. The stable, shape uniform, and narrow size distribution green nanocrystals are synthesized. The perovskite nanocrystal film exhibites excellent stability in 80% humidity air with only a 10% photoluminescence intensity drop after 16 h. Efficient and stable electroluminescence is demonstrated with an FWHM of 16 nm at 517 nm. The green devices shows a peak EQE of 24.13% with a lifetime T50 of 54 min at 10 000 cd m−2. Stable green perovskite nanocrystals are synthesized by a modified hot injection method, which control the nucleation and growth process with short‐chain length acids/bases and resurfacing agents. The fabricated green perovskite QLEDs achieves operation stability T50 of 54 min at 10 000 nits with high efficiency exceeding 24%. The peak emission is 517 nm with FWHM of 16 nm.