Dual‐Core and Quenching Resistance of Silicic Linkage‐Based Multiple Resonance Thermally Activated Delayed Fluorescence Emitters

Advanced Optical Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 17, 2025

Abstract Multiple resonance thermally activated delayed fluorescence (MR‐TADF) materials offer narrowband emission and efficiency but suffer from spectral broadening aggregation‐caused quenching (ACQ) at high doped concentrations. In this study, two novel silicic linkage‐based dual‐core MR‐TADF emitters, DMeSiB DPhSiB, are introduced, which effectively mitigate both concentration broadening. DPhSiB exhibit bluish‐green peaking 493 495 nm with full‐width half‐maximum (FWHM) values of 21 22 in toluene photoluminescence quantum yields exceeding 90% films. At a doping 5 wt%, the organic light‐emitting diodes (OLEDs) based on achieve maximum external efficiencies (EQE max s) 27.2% 28.6% narrow FWHMs 25 24 nm, respectively. Over range wt% to 20 OLEDs maintain EQE 23.5%, 21.4%, 19.2% 24.9%, 22.7%, 19.3%, Even concentration, devices broaden by only 2 or 3 reaching 27 nm. This structural design facilitates efficient luminescence while successfully suppressing ACQ, leading improved device performance.

Language: Английский

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Overcrowded steric engineering of through-space interactions for anti-quenching multi-resonance TADF materials

Chemical Engineering Journal, Journal Year: 2025, Volume and Issue: unknown, P. 163327 - 163327

Published: May 1, 2025

Language: Английский

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Fluorophore‐Bridge‐Fluorophore Architecture for Efficient Narrowband Pure Green Electroluminescence

Advanced Optical Materials, Journal Year: 2025, Volume and Issue: unknown

Published: May 6, 2025

Abstract Developing narrowband multiple resonance thermally activated delayed fluorescence (MR‐TADF) materials for concentration‐independent organic light‐emitting diodes (OLEDs) with high efficiency and color purity is still a challenge. Herein, fluorophore‐bridge‐fluorophore architecture developed, resulting in two MR‐TADF (BNCz‐n‐POABNCz POABNCz‐n‐POABNCz) by “face‐to‐face” arrangement of BNCz (based on carbazole unit) POABNCz phenoxazine groups) cores sterically the naphthalene bridge. Two show green emissions peaking at 501/516 nm full‐width half‐maximum values 30/33 toluene photoluminescence quantum yields 94%/87% doped films, respectively. Remarkably, POABNCz‐n‐POABNCz exhibits Commission Internationale de L'Eclairage coordinates (0.19, 0.71), reaching National Television System Committee standard pure emission. Furthermore, OLEDs D1 D2 composing BNCz‐n‐POABNCz illustrate maximum external efficiencies (EQE max ) 32.0% 33.6%, Even doping ratio 20 wt%, remains an EQE ≈28.5%.

Language: Английский

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Comprehensive Review on the Structural Diversity and Versatility of Multi-Resonance Fluorescence Emitters: Advance, Challenges, and Prospects toward OLEDs

Chemical Reviews, Journal Year: 2025, Volume and Issue: unknown

Published: May 9, 2025

Fluorescence emitters with a multiple-resonant (MR) effect have become research hotspot. These MR mainly consist of polycyclic aromatic hydrocarbons boron/nitrogen, nitrogen/carbonyl, and indolocarbazole frameworks. The staggered arrangement the highest occupied molecular orbital lowest unoccupied facilitates MR, resulting in smaller internal reorganization energy narrower emission bandwidth. Optimal charge separation suppresses gap between singlet triplet excited states, favoring thermally activated delayed fluorescence (TADF). MR-TADF materials, due to color purity high efficiency, are excellent candidates for organic light-emitting diodes. Nevertheless, significant challenges remain; particular, limitation imposed by alternated core configuration hinders their diversity versatility. Most existing materials concentrated blue-green range, only few red near-infrared spectra. This review provides timely comprehensive screening from pioneering work present. Our goal is gain understandings structure-performance relationship both basic advanced perspectives. Special emphasis placed on exploring correlations chemical structure, photophysical properties electroluminescent performance depth breadth an aim promote future development emitters.

Language: Английский

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Construction of Concentration Quenching‐Resistant Multi‐Resonance TADF Emitters via Positional Isomerization for OLEDs

Advanced Optical Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 9, 2024

Abstract Multiple resonance thermally activated delayed fluorescence (MR‐TADF) emitters are promising for high‐definition organic light‐emitting diodes (OLEDs) due to their high exciton utilization and color purity. However, strong interchromophore interactions cause most MR‐TADF with planar structures aggregate at doping concentrations, leading degraded efficiencies. Herein, using benzenesulfonyl‐functionalized dibenzothiophene sulfoximine steric effects, three (2SBN, 3SBN, 4SBN) synthesized by coupling the classic DtBuCzB skeleton different sites. Three exhibit green or blue‐green emission full width half maximum (FWHM) values less than 29 nm photoluminescence quantum yields exceeding 90%. OLEDs based on 2SBN, 4SBN achieve external efficiency (EQE max ) of 30.1%, 27%, 33.8%, respectively, a 5 wt.% concentration. Notably, distorted conformation suppressed intermolecular interaction, OLED remains EQE 28.9% concentration 20 wt.%. These results demonstrate feasibility molecular design modulate spatial conformations via positional isomerism develop reduced quenching.

Language: Английский

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Asymmetric structural strategy enables efficient MR-TADF emitters with low efficiency roll-off and doping-concentration insensitivity

Chemical Engineering Journal, Journal Year: 2024, Volume and Issue: 499, P. 155864 - 155864

Published: Sept. 16, 2024

Language: Английский

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Rational design of narrowband deep blue MR-TADF dendrimers for high performance solution-processed all fluorescence white OLEDs

Chemical Engineering Journal, Journal Year: 2024, Volume and Issue: unknown, P. 155350 - 155350

Published: Sept. 1, 2024

Language: Английский

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Recent Progress in Steric Modulation of MR-TADF Materials and Doping Concentration Independent OLEDs with Narrowband Emission

Chinese Journal of Structural Chemistry, Journal Year: 2024, Volume and Issue: unknown, P. 100451 - 100451

Published: Oct. 1, 2024

Language: Английский

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Highly Efficient Green Multi‐Resonance Thermally Activated Delayed Fluorescence Emitters with Suppression of Concentration Quenching

Advanced Optical Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 16, 2024

Abstract High‐efficiency multi‐resonance thermally activated delayed fluorescence (MR‐TADF) emitters with narrowband emission show great potential for organic light‐emitting diodes (OLEDs). However, their inherent planar rigid structures often lead to intractable challenges of spectral broadening, self‐quenching, and low device efficiency at high dopant concentrations. Herein, two steric isomers, BN‐1TPh BN‐2TPh, are designed by incorporating bulky shielding unit (1,3,5‐triphenylbenzene) the para‐ position B atom in MR skeleton hinder intermolecular interactions. They both enhanced photoluminescence quantum yields (PLQYs) as compared model compound BCzBN. The corresponding OLEDs based on BN‐2TPh display maximum external (EQE max ) values up 30.8% 30.4% narrow full width half (FWHM) bands 27 28 nm, respectively. It is worth noting that even doping ratio 20%, EQEs still maintained 24.8% 25.7% almost unchanged spectra. These results segregating MR‐TADF spatial structure can weaken interaction, which one effective ways resist aggregation‐caused quenching effect achieve high‐efficiency concentration‐indispensible OLEDs.

Language: Английский

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