Li Hongjin, Zhu Xiaofang, Zhang Dingshuo, Gao Yun, Feng Yifeng, Ma Zichao, Huang Jingyun, He Haiping, Ye Zhizhen, Dai Xingliang
School of Materials Science and Engineering, State Key Laboratory of Silicon and Advanced Semiconductor Materials, Zhejiang University, Hangzhou, 310027, P. R. China.
Wenzhou Key Laboratory of Novel Optoelectronic and Nano Materials and Engineering Research Centre of Zhejiang Province, Institute of Wenzhou, Zhejiang University, Wenzhou, 325006, P. R. China.
Nat Commun. 2024 Aug 3;15(1):6561. doi: 10.1038/s41467-024-50634-0.
Despite the promising candidacy of perovskite nanocrystals for light-emitting diodes, their pure red electroluminescence is hindered by low saturated luminance, severe external quantum efficiency roll-off, and inferior operational stability. Here, we report ultra-bright and stable pure red light-emitting diodes by manipulating Joule heat generation in the nanocrystal emissive layer and thermal management within the device. Diphenylphosphoryl azide-mediated regulation of the nanocrystal surface synergistically enhances the optical properties and carrier transport of the emissive layer, enabling reduced Joule heat generation and thus lowering the working temperature. These merits inhibit ion migration of the CsPb(Br/I) nanocrystal film, promising excellent spectra stability. Combined with the highly thermal-conductive sapphire substrates and implementation of pulse-driving mode, the pure red light-emitting diodes exhibit an ultra-bright luminance of 390,000 cd m, a peak external quantum efficiency of 25%, suppressed efficiency roll-off, an operational half-life of 20 hours, and superior spectral stability within 15 A cm.
尽管钙钛矿纳米晶体在发光二极管方面具有很好的应用前景，但其纯红色电致发光受到低饱和亮度、严重的外量子效率滚降和较差的操作稳定性的阻碍。在此，我们通过控制纳米晶体发光层中的焦耳热产生以及器件内部的热管理，报道了超亮且稳定的纯红色发光二极管。二苯基磷酰叠氮介导的纳米晶体表面调控协同增强了发光层的光学性能和载流子传输，减少了焦耳热的产生，从而降低了工作温度。这些优点抑制了CsPb(Br/I)纳米晶体薄膜的离子迁移，有望实现优异的光谱稳定性。结合高导热蓝宝石衬底和脉冲驱动模式的实施，纯红色发光二极管表现出390,000 cd m的超亮亮度、25%的峰值外量子效率、抑制的效率滚降、20小时的操作半衰期以及在15 A cm内的优异光谱稳定性。
