無機ペロブスカイトLEDの空間閉じ込め設計（USTC Develops Weakly Space-Confined All-Inorganic Perovskite Light-Emitting Diodes）

2025-06-12 中国科学院（CAS）

＜関連情報＞

• https://english.cas.cn/newsroom/research_news/chem/202506/t20250610_1045307.shtml
• https://www.nature.com/articles/s41586-025-09137-1

発光ダイオード用弱空間閉じ込め型無機ペロブスカイト Weakly space-confined all-inorganic perovskites for light-emitting diodes

Chenchen Peng,Haitao Yao,Othman Ali,Wenjing Chen,Yingguo Yang,Zongming Huang,Hui Liu,Jianyu Li,Tao Chen,Zhijian Li,Mei Sun,Hongmin Zhou,Xiangru Tao,Nana Wang,Jianpu Wang & Zhengguo Xiao
Nature  Published:11 June 2025
DOI:https://doi.org/10.1038/s41586-025-09137-1

Abstract

Metal halide perovskites are promising materials for light-emitting diodes (LEDs)^1,2,3,4. Spatially confining charge carriers using nanocrystal/quantum dots^5,6,7,8,9, low-dimensional perovskites^10,11,12,13 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 lifetime^{6,7,10,11,12,14,15,16,17}. 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 1,000 mA cm⁻² and a brightness of over 1,167,000 cd m⁻². Furthermore, benefiting from the suppressed ion migration and better thermal stability, the extrapolated half-lifetime of the weakly space-confined PeLEDs increased to 185,600 h under an initial luminance of 100 cd m⁻² at room temperature. Our work is a new approach for designing efficient, bright and stable PeLEDs for real applications.