Journal Article

Edge stabilization in reduced-dimensional perovskites

Lu, Zheng-Hong, Saidaminov, Makhsud I., Tan, Hairen, Wei, Nini, Ma, Dongxin, García de Arquer, F. Pelayo, Liu, Mengxia, Quintero-Bermudez, Rafael, Bakr, Osman M., Zhao, Yongbiao, Hofkens, Johan, Todorović, Petar, Pan, Jun, Sargent, Edward H., Fan, James Z., Na Quan, Li, Sabatini, Randy, Anjum, Dalaver H., Gao, Liang, Bladt, Eva, Walters, Grant, Voznyy, Oleksandr, Yuan, Haifeng, Tang, Jiang, Emwas, Abdul-Hamid, McCamant, David W., Li, Yiying, Piontkowski, Zachary, Roeffaers, Maarten B. J., Bals, Sara

2020

Overview

Reduced-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 m −2 ; their maximum luminance is 4.5 × 10 4  cd m −2 (corresponding to an EQE of 5%); and, at 4000 cd m −2 , they achieve an operational half-lifetime of 3.5 h. Reduced-dimensional halide perovskites are promising for light-emitting diodes but suffer from photo-degradation. Here Quan et al. identify the edge of the perovskite nanoplatelets as the degradation channels and use phosphine oxides to passivate the edges and boost device performance and lifetime.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 639/166 / 639/301 / Crystallization / Humanities and Social Sciences / Light emitting diodes / Luminance / multidisciplinary / Organic light emitting diodes / Oxides / Perovskites / Phosphine / Phosphines / Photodegradation / Photoluminescence / Photons / Photooxidation / Quantum efficiency / Science / Science (multidisciplinary) / Service life assessment / Stabilization / Superoxide