Unravelling Alkali-Metal-Assisted Domain Distribution of Quasi-2D Perovskites for Cascade Energy Transfer toward Efficient Blue Light-Emitting Diodes
Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review
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Original language | English |
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Article number | 2200393 |
Journal / Publication | Advanced Science |
Volume | 9 |
Issue number | 20 |
Online published | 13 May 2022 |
Publication status | Published - 15 Jul 2022 |
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Link to Scopus | https://www.scopus.com/record/display.uri?eid=2-s2.0-85129816261&origin=recordpage |
Permanent Link | https://scholars.cityu.edu.hk/en/publications/publication(86850482-7188-45b3-9801-86bc6608ac6f).html |
Abstract
Solution processable quasi-2D (Q-2D) perovskite materials are emerging as a promising candidate for blue light source in full-color display applications due to their good color saturation property, high brightness, and spectral tunability. Herein, an efficient energy cascade channel is developed by introducing sodium bromide (NaBr) in phenyl-butylammonium (PBA)-containing mixed-halide Q-2D perovskites for a blue perovskite light-emitting diode (PeLED). The incorporation of alkali metal contributes to the nucleation and growth of Q-2D perovskites into graded distribution of domains with different layer number <n>. The study of excitation dynamics by transient absorption (TA) spectroscopy confirms that NaBr induces more Q-2D perovskite phases with small n number, providing a graded energy cascade pathway to facilitate more efficient energy transfer processes. In addition, the nonradiative recombination within the Q-2D perovskites is significantly suppressed upon Na+ incorporation, as validated by the trap density estimation. Consequently, the optimized blue PeLEDs manifest a peak external quantum efficiency (EQE) of 7.0% emitting at 486 nm with a maximum luminance of 1699 cd m−2. It is anticipated that these findings will improve the understanding of alkali-metal-assisted optimization of Q-2D perovskites and pave the way toward high-performance blue PeLEDs.
Research Area(s)
- alkali metal halide, domain distribution, perovskite light-emitting diode, quasi-2D perovskite
Citation Format(s)
Unravelling Alkali-Metal-Assisted Domain Distribution of Quasi-2D Perovskites for Cascade Energy Transfer toward Efficient Blue Light-Emitting Diodes. / Cai, Wanqing; Ali, Muhammad Umair; Liu, Ping et al.
In: Advanced Science, Vol. 9, No. 20, 2200393, 15.07.2022.
In: Advanced Science, Vol. 9, No. 20, 2200393, 15.07.2022.
Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review
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