Pan Gencai, Bai Xue, Xu Wen, Chen Xu, Zhai Yue, Zhu Jinyang, Shao He, Ding Nan, Xu Lin, Dong Biao, Mao Yanli, Song Hongwei
State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, P. R. China.
School of Physics and Electronics, Henan University, No. 1, Jinming Street, Kaifeng 475004, P. R. China.
ACS Appl Mater Interfaces. 2020 Mar 25;12(12):14195-14202. doi: 10.1021/acsami.0c01074. Epub 2020 Mar 11.
In recent years, significant advances have been achieved in the red and green perovskite quantum dot (PQD)-based light-emitting diodes (LEDs). However, the performances of the blue perovskite LEDs are still seriously lagging behind that of the green and red counterparts. Herein, we successfully developed Ni ion-doped CsPbClBr PQDs through the room-temperature supersaturated recrystallization synthetic approach. We simultaneously realized the doping of various concentrations of Ni cations and modulated the Cl/Br element ratios by introducing different amounts of NiCl solution in the reaction medium. Using the synthetic method, not only the emission wavelength from 508 to 432 nm of Ni ion-doped CsPbClBr QDs was facially adjusted, but also the photoluminescence quantum yield (PLQY) of PQDs was greatly improved due to efficient removal of the defects of the PQDs. Thus, the blue emission at 470 nm with PLQY of 89% was achieved in 2.5% Ni ion-doped CsPbClBr QDs, which increased nearly three times over that of undoped CsPbClBr QDs and was the highest for the CsPbX PQDs with blue emission, fulfilling the National Television System Committee standards. Benefiting from the highly luminous Ni ion-doped PQDs, the blue-emitting LED at 470 nm was obtained, exhibiting an external quantum efficiency of 2.4% and a maximum luminance of 612 cd/m, which surpassed the best performance reported previously for the corresponding blue-emitting PQD-based LED.
近年来，基于红色和绿色钙钛矿量子点（PQD）的发光二极管（LED）取得了重大进展。然而，蓝色钙钛矿LED的性能仍严重落后于绿色和红色同类产品。在此，我们通过室温过饱和重结晶合成方法成功开发了镍离子掺杂的CsPbClBr PQD。我们同时实现了不同浓度镍阳离子的掺杂，并通过在反应介质中引入不同量的NiCl溶液来调节Cl/Br元素比例。使用该合成方法，不仅可以轻松调节镍离子掺杂的CsPbClBr量子点从508到432nm的发射波长，而且由于有效去除了量子点的缺陷，量子点的光致发光量子产率（PLQY）也得到了极大提高。因此，在2.5%镍离子掺杂的CsPbClBr量子点中实现了470nm处的蓝色发射，PLQY为89%，比未掺杂的CsPbClBr量子点提高了近三倍，是具有蓝色发射的CsPbX PQD中最高的，符合美国国家电视系统委员会标准。受益于高发光的镍离子掺杂量子点，获得了470nm处的蓝色发光LED，其外量子效率为2.4%，最大亮度为612cd/m²，超过了此前报道的相应蓝色发光PQD基LED的最佳性能。
