Chiral Multi-Resonance TADF Emitters Exhibiting Narrowband Circularly Polarized Electroluminescence with an EQE of 37.2 .
Angew Chem Int Ed Engl
; 61(30): e202202227, 2022 Jul 25.
Article
em En
| MEDLINE
| ID: mdl-35536020
ABSTRACT
Highly efficient circularly polarized luminescence (CPL) emitters with narrowband emission remain a formidable challenge for circularly polarized OLEDs (CP-OLEDs). Here, a promising strategy for developing chiral emitters concurrently featuring multi-resonance thermally activated delayed fluorescence (MR-TADF) and circularly polarized electroluminescence (CPEL) is demonstrated by the integration of molecular rigidity, central chirality and MR effect. A pair of chiral green emitters denoted as (R)-BN-MeIAc and (S)-BN-MeIAc is designed. Benefited by the rigid and quasi-planar MR-framework, the enantiomers not only display mirror-image CPL spectra, but also exhibit TADF properties with a high photoluminescence quantum yield of 96 %, a narrow FWHM of 30â
nm, and a high horizontal dipole orientation of 90 % in the doped film. Consequently, the enantiomer-based CP-OLEDs achieved excellent external quantum efficiencies of 37.2 % with very low efficiency roll-off, representing the highest device efficiency of all the reported CP-OLEDs.
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01-internacional
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MEDLINE
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En
Ano de publicação:
2022
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Article