Multifunctional Crystal Regulation Enables Efficient and Stable Sky-Blue Perovskite Light-Emitting Diodes

作者：Shen, Yang; Li, Yan-Qing^*; Zhang, Kai; Zhang, Liu-Jiang; Xie, Feng-Ming; Chen, Li; Cai, Xiao-Yi; Lu, Yu; Ren, Hao; Gao, Xingyu; Xie, Haijiao; Mao, Hongying; Kera, Satoshi; Tang, Jian-Xin^*

来源：Advanced Functional Materials, 2022, 32(41): 2206574.

DOI：10.1002/adfm.202206574

• defect passivation
• high efficiency
• perovskite light-emitting diodes
• sky-blue emission
• stability

Perovskite light-emitting didoes (PeLEDs) have shown considerable potential in solution-processable display applications. However, the performance of blue PeLEDs in terms of efficiency and stability hinders their practicality on account of severe trap-mediated nonradiative recombination losses and halide phase segregation. To ameliorate these issues, mixed-halide sky-blue perovskite materials are strategically modulated through crystal defect passivation with a trifurcate isocyanate oligomer, which leads to the synergistical suppression of charge trap density and halide ion migration. The proposed approach enables the performance improvement for sky-blue PeLEDs, exhibiting a peak external quantum efficiency of 14.82% and spectrally stable emission at 487 nm. In addition, prolonged operational lifetime and enhanced capability of moisture resistance are achieved simultaneously, approaching a half-lifetime of approximate to 2900 s at an initial brightness of 178 cd m(-2).

• 单位
  苏州大学; 中国科学院; 杭州师范大学