Wei Jianwu, Li Jiong, Duan Chenghao, Yuan Ligang, Zou Shibing, Pang Qi, Yan Keyou
School of Chemistry and Chemical Engineering, Guangxi Key Laboratory of Electrochemical Energy Materials, Guangxi University, Nanning, 530004, P. R. China.
School of Environment and Energy, State Key Lab of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, 510000, P. R. China.
Small. 2023 May;19(20):e2207769. doi: 10.1002/smll.202207769. Epub 2023 Feb 17.
The rolling-off phenomenon of device efficiency at high current density caused by quenching of luminescence in perovskite light-emitting diodes (PeLED) is challenging to be solved. Here, 2-amino-5-iodopyrazine (AIPZ) is dissolved in a mixed solvent of chlorobenzene (CB)/isopropanol (IPA) (7:3 volume ratio) for surface post-treatment of FAPbI perovskite film. The interaction of AIPZ and perovskite surface not only balances the charge injection but also passivates defects to enhance radiative recombination in PeLED. Therefore, the PeLED champion yields peak external quantum efficiency reaching 23.2% at the current density of 45 mA cm with a radiance brightness of 290 W sr m . More importantly, the rolling-off of device efficiency is significantly reduced. The lowest rolling-off devices can maintain 80% of peak EQE (22.1%) at a high current density of 460 mA cm , whereas the control device only retains 25% of the peak EQE value. This work provides an effective strategy to improve performance and reduce the EQE rolling-off of PeLED for practical application.
钙钛矿发光二极管（PeLED）中由于发光猝灭导致的高电流密度下器件效率的滚降现象难以解决。在此，将2-氨基-5-碘吡嗪（AIPZ）溶解于氯苯（CB）/异丙醇（IPA）（体积比7:3）的混合溶剂中，用于FAPbI钙钛矿薄膜的表面后处理。AIPZ与钙钛矿表面的相互作用不仅平衡了电荷注入，还钝化了缺陷，以增强PeLED中的辐射复合。因此，PeLED的最佳器件在45 mA cm²的电流密度下实现了23.2%的峰值外量子效率，辐射亮度为290 W sr⁻¹ m⁻²。更重要的是，器件效率的滚降显著降低。最低滚降器件在460 mA cm²的高电流密度下可保持峰值EQE（22.1%）的80%，而对照器件仅保留峰值EQE值的25%。这项工作为提高PeLED的性能并降低其EQE滚降以实现实际应用提供了一种有效策略。
