High-Efficiency Pure-Red Perovskite Quantum-Dot Light-Emitting Diodes

作者：Mingyuan Xie, Jie Guo, Xiaoyu Zhang, Chenghao Bi, Lin Zhang, Zema Chu, Weitao Zheng, Jingbi You, Jianjun Tian · 发表于：Nano Letters · 年份：2022 · DOI：10.1021/acs.nanolett.2c03062 · 被引用次数：163 · 研究领域：Perovskite Materials and Applications、Quantum Dots Synthesis And Properties、Organic Light-Emitting Diodes Research

It is still challenging to achieve high-efficiency pure-red (620–650 nm wavelength) perovskite light-emitting diodes (PeLEDs). Herein, we report pure-red PeLEDs with Commission Internationale de l’Eclairage coordinates (0.703, 0.297) meeting the Rec. 2020, an external quantum efficiency of 20.8%, and a luminance of 3775 cd/m 2 . This design is based on the strong quantum confinement CsPbI 3 quantum dots (QDs) capped by composite ligands of 3-phenyl-1-propylamine and tetrabutylammonium iodide. This strategy stabilized the structure of the strong-confined QDs and reduced the influence of the electric field-induced Stark effect on the PeLEDs. Furthermore, the exciton binding energy of the QDs was decreased by the composited ligands to suppress Auger recombination within the devices. Additionally, the valence-band maximum of the QDs was lifted to match the hole-transport layer, thus balancing charge injection in the PeLEDs. Our device also demonstrated a stable electroluminescence spectrum and a lifetime of 5.6 times longer than the control device.