1. Donor-σ-Acceptor Motifs: Thermally Activated Delayed Fluorescence Emitters with Dual Upconversion.
- Author
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Geng, Yan, D'Aleo, Anthony, Inada, Ko, Cui, Lin‐Song, Kim, Jong Uk, Nakanotani, Hajime, and Adachi, Chihaya
- Subjects
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CHARGE transfer , *FLUORESCENCE , *QUANTUM efficiency , *ACTIVATION (Chemistry) , *LIGHT emitting diodes - Abstract
A family of organic emitters with a donor-σ-acceptor (D-σ-A) motif is presented. Owing to the weakly coupled D-σ-A intramolecular charge-transfer state, a transition from the localized excited triplet state (3LE) and charge-transfer triplet state (3CT) to the charge-transfer singlet state (1CT) occurred with a small activation energy and high photoluminescence quantum efficiency. Two thermally activated delayed fluorescence (TADF) components were identified, one of which has a very short lifetime of 200-400 ns and the other a longer TADF lifetime of the order of microseconds. In particular, the two D-σ-A materials presented strong blue emission with TADF properties in toluene. These results will shed light on the molecular design of new TADF emitters with short delayed lifetimes. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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