Zhou Xin, Yang Mengmeng, Shen Chao, Lian Linyuan, Hou Lintao, Zhang Jibin
National & Local Joint Engineering Research Center of Semiconductor Display and Optical Communication Devices, South China University of Technology, Guangzhou 510641, China.
Guangdong Provincial Key Laboratory of Semiconductor Micro Display, Foshan Nationstar Optoelectronics Company Ltd., Foshan 528000, China.
Nano Lett. 2024 Mar 27;24(12):3719-3726. doi: 10.1021/acs.nanolett.4c00220. Epub 2024 Mar 14.
Mixed-halide CsPb(Br/I) perovskite quantum dots (QDs) are regarded as one of the most promising candidates for pure-red perovskite light-emitting diodes (PeLEDs) due to their precise spectral tuning property. However, the lead-rich surface of these QDs usually results in halide ion migration and nonradiative recombination loss, which remains a great challenge for high-performance PeLEDs. To solve the above issues, we employ a chelating agent of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid hydrate (DOTA) to polish the lead-rich surface of the QDs and meanwhile introduce a new ligand of 2,3-dimercaptosuccinic acid (DMSA) to passivate surface defects of the QDs. This synchronous post-treatment strategy results in high-quality CsPb(Br/I) QDs with suppressed halide ion migration and an improved photoluminescence quantum yield, which enables us to fabricate spectrally stable pure-red PeLEDs with a peak external quantum efficiency of 23.2%, representing one of the best performance pure-red PeLEDs based on mixed-halide CsPb(Br/I) QDs reported to date.
混合卤化物CsPb(Br/I)钙钛矿量子点（QDs）因其精确的光谱调谐特性，被视为纯红色钙钛矿发光二极管（PeLEDs）最有前景的候选材料之一。然而，这些量子点富含铅的表面通常会导致卤离子迁移和非辐射复合损失，这仍然是高性能PeLED面临的巨大挑战。为了解决上述问题，我们采用1,4,7,10-四氮杂环十二烷-1,4,7,10-四乙酸水合物（DOTA）作为螯合剂来修饰量子点富含铅的表面，同时引入一种新的配体2,3-二巯基琥珀酸（DMSA）来钝化量子点的表面缺陷。这种同步后处理策略得到了高质量的CsPb(Br/I)量子点，抑制了卤离子迁移并提高了光致发光量子产率，这使我们能够制备出光谱稳定的纯红色PeLED，其峰值外量子效率为23.2%，代表了迄今为止报道的基于混合卤化物CsPb(Br/I)量子点的最佳性能纯红色PeLED之一。
