High stability and luminescence efficiency in donor-acceptor neutral radicals not following the Aufbau principle.
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Authors
Guo, Haoqing
Peng, Qiming
Chen, Xian-Kai
Gu, Qinying
Dong, Shengzhi
Evans, Emrys
Ai, Xin
Zhang, Ming
Coropceanu, Veaceslav
Brédas, Jean-Luc
Li, Feng
Journal Title
Nature Materials
ISSN
1476-1122
Publisher
Springer Nature
Volume
18
Pages
977-984
Language
eng
Type
Article
This Version
AM
Metadata
Show full item recordCitation
Guo, H., Peng, Q., Chen, X., Gu, Q., Dong, S., Evans, E., Gillett, A., et al. (2019). High stability and luminescence efficiency in donor-acceptor neutral radicals not following the Aufbau principle.. Nature Materials, 18 977-984. https://doi.org/10.1038/s41563-019-0433-1
Abstract
With their unusual electronic structures, organic radical molecules display luminescence properties potentially relevant to lighting applications; yet, their luminescence quantum yield and stability lag behind those of other organic emitters. Here, we designed donor-acceptor neutral radicals based on an electron-poor perchlorotriphenylmethyl or tris(2,4,6-trichlorophenyl)methyl radical moiety combined with different electron-rich groups. Experimental and quantum-chemical studies demonstrate that the molecules do not follow the Aufbau principle: the singly occupied molecular orbital is found to lie below the highest (doubly) occupied molecular orbital. These donor-acceptor radicals have a strong emission yield (up to 54%) and high photostability, with estimated half-lives reaching up to several months under pulsed ultraviolet laser irradiation. Organic light-emitting diodes based on such a radical emitter show deep-red/near-infrared emission with a maximal external quantum efficiency of 5.3%. Our results provide a simple molecular-design strategy for stable, highly luminescent radicals with non-Aufbau electronic structures.
Sponsorship
Includes EPSRC.
Funder references
EPSRC (1642195)
EPSRC (1642195)
EPSRC (EP/M005143/1)
EPSRC (EP/M01083X/1)
Identifiers
External DOI: https://doi.org/10.1038/s41563-019-0433-1
This record's URL: https://www.repository.cam.ac.uk/handle/1810/299679
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