Highly efficient multi-resonance thermally activated delayed fluorescence material toward a BT.2020 deep-blue emitter.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38565868.
- Also identified by DOI 10.1038/s41467-024-46619-8 and PMC identifier 10987657.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
An ultrapure deep-blue multi-resonance-induced thermally activated delayed fluorescence material (DOB2-DABNA-A) is designed and synthesized. Benefiting from a fully resonating extended helical π-conjugated system, this compound has a small ΔE<sub>ST</sub> value of 3.6 meV and sufficient spin-orbit coupling to exhibit a high-rate constant for reverse intersystem crossing (k<sub>RISC</sub> = 1.1 × 10<sup>6 </sup>s<sup>-1</sup>). Furthermore, an organic light-emitting diode employing DOB2-DABNA-A as an emitter is fabricated; it exhibits ultrapure deep-blue emission at 452 nm with a small full width at half maximum of 24 nm, corresponding to Commission Internationale de l'Éclairage (CIE) coordinates of (0.145, 0.049). The high k<sub>RISC</sub> value reduces the efficiency roll-off, resulting in a high external quantum efficiency (EQE) of 21.6% at 1000 cd m<sup>-2</sup>.