A hierarchical shell locks and stabilizes perovskite nanocrystals with near-unity quantum yield
Qingsen Zeng, Yue Zhao, Sunghee Park, Huanyu Zhou, Hyun-Joon Shim, Tianshu Li, Jinseok Ryu, Min-Jun Sung, Xian Wei Chua, Eojin Yoon, Barney A. I. Lewis, S. M. Woo, Michele Forzatti, Min Ju Kim, Eun A. Kim, Linjie Dai, Jinhyeong Jang, Yipeng Tang, Jin Jung Kweon, Hao Chen, Kyung Yeon Jang, Dong-Hyeok Kim, Woo Jin Jeong, Joo Sung Kim, Hyejin Lee, Kyueun Lim, Seong-Yong Cho, Chan Beum Park, S.K. Lee, M. Joon Kim, Henk J. Bolink, Bin Hu, A. T. Walsh, Samuel D. Stranks, Tae-Woo Lee
Abstract
Solid-state emitters have exhibited external quantum yields (EQYs) below 65%, with no system combining unity photoluminescence quantum yield (PLQY) and commercially viable stability. These limitations are most pronounced in colloidal perovskite nanocrystals (PeNCs), given their soft ionic lattices and labile surfaces. We introduce a hierarchical shell (HS) structure comprising interbonded PbSO 4 -SiO 2 -polymer multilayers that simultaneously locks and stabilizes soft lattices and labile interfaces. HS-CsPbBr 3 PeNC films exhibit T 90 (10% PLQY loss) = 3211 hours under accelerated 60°C, 90% relative humidity (RH) and T 90 = 12,000 hours under blue-light exposure. HS strategy generalizes across PeNC compositions—including mixed-halide, mixed-cation, iodide, and hybrid PeNCs—and enables MAPbBr 3 with extended T 90 = 3900 hours (60°C, 90% RH) and T 90 = 27,234 hours (blue light). Moreover, HS-MAPbBr 3 films with 100.0% PLQY eliminate self-absorption losses and achieve an EQY of 91.4%, approaching the theoretical maximum. The HS barrier also prevents lead leakage for safety of large-area, high-resolution displays and bio-optoelectronics.