中国科学技术大学肖正国团队近日研究了用于发光二极管的弱空间约束全无机钙钛矿。相关论文于2025年6月11日发表在《自然》杂志上。

金属卤化物钙钛矿是发光二极管（LED）的有前景的材料。使用纳米晶体/量子点、低维钙钛矿和超薄钙钛矿层的空间限制电荷载流子都被用来提高钙钛矿LED（PeLED）的外部量子效率。然而，大多数空间受限的钙钛矿都会遭受严重的俄歇复合、离子迁移和热不稳定性，导致亮度和使用寿命有限。 

研究组报告了一种基于弱空间受限、大晶粒全无机钙钛矿晶体的替代策略。牺牲添加剂，即次磷酸和氯化铵，用于诱导溴化铯铅的成核和结晶，从而产生具有最小陷阱密度和高光致发光量子产率的单晶晶粒。得益于高载流子迁移率和抑制的俄歇复合，研究组获得了高效的PeLED，其外部量子效率达到22.0%，在接近1000 mA cm^-2的高电流密度下保持在20%以上 ，亮度超过1167000 cd m⁻²?。此外，得益于抑制的离子迁移和更好的热稳定性，在室温、初始亮度100 cd m⁻²下，弱空间限制的PeLED的外推半衰期增加到185600 h。该工作为实际应用设计高效、明亮和稳定的PeLED提供了新策略。

附：英文原文

Title: Weakly space-confined all-inorganic perovskites for light-emitting diodes

Author: Peng, Chenchen, Yao, Haitao, Ali, Othman, Chen, Wenjing, Yang, Yingguo, Huang, Zongming, Liu, Hui, Li, Jianyu, Chen, Tao, Li, Zhijian, Sun, Mei, Zhou, Hongmin, Tao, Xiangru, Wang, Nana, Wang, Jianpu, Xiao, Zhengguo

Issue&Volume: 2025-06-11

Abstract: Metal halide perovskites are promising materials for light-emitting diodes (LEDs)1,2,3,4. Spatially confining charge carriers using nanocrystal/quantum dots5,6,7,8,9, low-dimensional perovskites10,11,12,13 and ultrathin perovskite layers14 have all been used to improve the external quantum efficiency of perovskite LEDs (PeLEDs). However, most strongly space-confined perovskites suffer from severe Auger recombination, ion migration and thermal instability, resulting in limited brightness and operational lifetime6,7,10,11,12,14,15,16,17. Here, we report an alternative strategy based on weakly space-confined, large-grained crystals of all-inorganic perovskite. Sacrificial additives, namely, hypophosphorous acid and ammonium chloride, were used to induce nucleation and crystallization of caesium lead bromide, resulting in monocrystal grains with minimized trap density and a high photoluminescence quantum yield. Benefiting from the high carrier mobility and suppressed Auger recombination, we obtained efficient PeLEDs with an external quantum efficiency reaching 22.0%, which remained above 20% at a high current density near 1,000mAcm2 and a brightness of over 1,167,000cdm2. Furthermore, benefiting from the suppressed ion migration and better thermal stability, the extrapolated half-lifetime of the weakly space-confined PeLEDs increased to 185,600h under an initial luminance of 100cdm2 at room temperature. Our work is a new approach for designing efficient, bright and stable PeLEDs for real applications.

DOI: 10.1038/s41586-025-09137-1

Source: https://www.nature.com/articles/s41586-025-09137-1