Color-stable highly luminescent sky-blue perovskite light-emitting diodes

• Main Authors: Xing, Jun, Zhao, Yongbiao, Askerka, Mikhail, Quan, Li Na, Gong, Xiwen, Zhao, Weijie, Zhao, Jiaxin, Tan, Hairen, Long, Guankui, Gao, Liang, Yang, Zhenyu, Voznyy, Oleksandr, Tang, Jiang, Lu, Zheng-Hong, Xiong, Qihua, Sargent, Edward H.
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2018
• Subjects: Perovskite Light-emitting Diodes; DRNTU::Engineering::Electrical and electronic engineering; Color-stable
• Online Access: https://hdl.handle.net/10356/88941; http://hdl.handle.net/10220/46057
• Institution: Nanyang Technological University

Perovskite light-emitting diodes (PeLEDs) have shown excellent performance in the green and near-infrared spectral regions, with high color purity, efficiency, and brightness. In order to shift the emission wavelength to the blue, compositional engineering (anion mixing) and quantum-confinement engineering (reduced-dimensionality) have been employed. Unfortunately, LED emission profiles shift with increasing driving voltages due to either phase separation or the coexistence of multiple crystal domains. Here we report color-stable sky-blue PeLEDs achieved by enhancing the phase monodispersity of quasi-2D perovskite thin films. We selected cation combinations that modulate the crystallization and layer thickness distribution of the domains. The perovskite films show a record photoluminescence quantum yield of 88% at 477 nm. The corresponding PeLEDs exhibit stable sky-blue emission under high operation voltages. A maximum luminance of 2480 cd m−2 at 490 nm is achieved, fully one order of magnitude higher than the previous record for quasi-2D blue PeLEDs.