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.
Original language | English (US) |
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Pages (from-to) | 977-984 |
Number of pages | 8 |
Journal | Nature materials |
Volume | 18 |
Issue number | 9 |
DOIs | |
State | Published - Sep 1 2019 |
Externally published | Yes |
ASJC Scopus subject areas
- General Chemistry
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering