Wang Lintao, Shi Zhifeng, Ma Zhuangzhuang, Yang Dongwen, Zhang Fei, Ji Xinzhen, Wang Meng, Chen Xu, Na Guangren, Chen Shu, Wu Di, Zhang Yu, Li Xinjian, Zhang Lijun, Shan Chongxin
Key Laboratory of Materials Physics of Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Daxue Road 75, Zhengzhou 450052, China.
State Key Laboratory on Integrated Optoelectronics, Key Laboratory of Automobile Materials of MOE, and College of Materials Science and Engineering, Jilin University, Changchun 130012, China.
Nano Lett. 2020 May 13;20(5):3568-3576. doi: 10.1021/acs.nanolett.0c00513. Epub 2020 Apr 7.
Currently, the blue perovskite light-emitting diodes (PeLEDs) suffer from a compromise in lead toxicity and poor operation stability, and most previous studies have struggled to meet the crucial blue NTSC standard. In this study, electrically driven deep-blue LEDs (∼445 nm) based on zero-dimensional (0D) CsCuI nanocrystals (NCs) were demonstrated with the color coordinates of (0.16, 0.07) and a high external quantum efficiency of ∼1.12%, comparable with the best-performing blue LEDs based on lead-halide perovskites. Encouraged by the remarkable stability of CsCuI NCs against heat and environmental oxygen/moisture, the proposed device was operated in a continuous current mode for 170 h, producing a record half-lifetime of ∼108 h. The device stability was further verified by an aggressive thermal cycling test (300-360-300 K) and a 35-day storage test. Together with the eco-friendly features and facile colloidal synthesis technique, the 0D CsCuI NCs can be therefore regarded as a promising candidate for deep-blue LEDs applications.
目前，蓝色钙钛矿发光二极管（PeLEDs）存在铅毒性和运行稳定性差的问题，而且大多数先前的研究都难以达到关键的蓝色NTSC标准。在本研究中，基于零维（0D）CsCuI纳米晶体（NCs）的电驱动深蓝色发光二极管（445 nm）被展示出来，其色坐标为（0.16, 0.07），外部量子效率高达1.12%，与基于卤化铅钙钛矿的性能最佳的蓝色发光二极管相当。受CsCuI NCs对热和环境中的氧气/水分具有显著稳定性的鼓舞，所提出的器件以连续电流模式运行了170小时，产生了创纪录的约108小时的半衰期。通过剧烈的热循环测试（300 - 360 - 300 K）和35天的存储测试进一步验证了器件的稳定性。结合其环保特性和简便的胶体合成技术，因此0D CsCuI NCs可被视为深蓝色发光二极管应用的有前途的候选材料。
