Na Quan, LiMa, DongxinZhao, YongbiaoVoznyy, OleksandrYuan, HaifengBladt, EvaPan, JunGarcía de Arquer, F. PelayoSabatini, RandyPiontkowski, ZacharyEmwas, Abdul-HamidTodorović, PetarQuintero-Bermudez, RafaelWalters, GrantFan, James Z.Liu, MengxiaTan, HairenSaidaminov, Makhsud I.Gao, LiangLi, YiyingAnjum, Dalaver H.Wei, NiniTang, JiangMcCamant, David W.Roeffaers, Maarten B. J.Bals, SaraHofkens, JohanBakr, Osman M.Lu, Zheng-HongSargent, Edward H.2025-01-232025-01-232020Quan, L. N., Ma, D., Zhao, Y., Voznyy, O., Yuan, H., Bladt, E., Pan, J., De Arquer, F. P. G., Sabatini, R., Piontkowski, Z., Emwas, A., Todorović, P., Quintero-Bermudez, R., Walters, G., Fan, J. Z., Liu, M., Tan, H., Saidaminov, M. I., Gao, L., . . . Sargent, E. H. (2020). Edge stabilization in reduced-dimensional perovskites. Nature Communications, 11(1). https://doi.org/10.1038/s41467-019-13944-2https://doi.org/10.1038/s41467-019-13944-2https://hdl.handle.net/1828/20992Reduced-dimensional perovskites are attractive light-emitting materials due to their efficient luminescence, color purity, tunable bandgap, and structural diversity. A major limitation in perovskite light-emitting diodes is their limited operational stability. Here we demonstrate that rapid photodegradation arises from edge-initiated photooxidation, wherein oxidative attack is powered by photogenerated and electrically-injected carriers that diffuse to the nanoplatelet edges and produce superoxide. We report an edge-stabilization strategy wherein phosphine oxides passivate unsaturated lead sites during perovskite crystallization. With this approach, we synthesize reduced-dimensional perovskites that exhibit 97±3% photoluminescence quantum yields and stabilities that exceed 300 h upon continuous illumination in an air ambient. We achieve green-emitting devices with a peak external quantum efficiency (EQE) of 14% at 1000 cd m2; their maximum luminance is 4.5×104 cd m2 (corresponding to an EQE of 5%); and, at 4000 cd m2, they achieve an operational half-lifetime of 3.5 h.enAttribution 4.0 InternationalArticleDepartment of ChemistryDepartment of Electrical and Computer Engineering