Bifunctional Group Modulation Strategy Enables MR‐TADF Electroluminescence Toward BT.2020 Green Light Standard

Advanced Materials, Год журнала: 2025, Номер unknown

Опубликована: Янв. 23, 2025

Abstract Herein, a parallel “bifunctional group” modulation method is proposed to achieve controlled of the emission wavelength and full‐width at half‐maximum (FWHM) values. As result, three proof‐of‐concept emitters, namely DBNDS‐TPh, DBNDS‐DFPh, DBNDS‐CNPh, are designed synthesized, with first functional dibenzo[ b,d ]thiophene unit concurrently reducing bandgap elevate their triplet state energy. A second group 1 , ′: 3 ′, ″‐ triphenyl electron acceptors 1,3‐difluorobenzene benzonitrile respectively, deepen HOMO LUMO levels. Accordingly, CIE coordinates DBNDS‐CNPh (0.13, 0.77), (0.14, 0.76) in dilute toluene solution. This marks instance achieving y value 0.77 solutions. Significantly, non‐sensitized pure‐green OLEDs based on DBNDS‐TPh DBNDS‐DFPh demonstrate peak EQE 35.0% 34.5%, corresponding (0.18, 0.75), (0.17, doping concentration wt.%, representing green OLED reaching 0.76 bottom‐emitting device structure as reported literature.

Язык: Английский

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Carbonyl‐Based Narrowband Emitters Peripherally Decorated by Sulfone‐Containing Spiro Structures

Advanced Functional Materials, Год журнала: 2024, Номер 34(32)

Опубликована: Март 26, 2024

Abstract Sulfone group plays a pivotal role in narrowing emission spectra, while, precise modification with sulfone for carbonyl‐based narrowband emitters that maintain high color purity remains challenging. Herein, comprehensive exploration of the function is performed various sulfur valences and positions fused into traditional unit QAO, namely SpiroS‐QAO, SpiroSO 2 ‐QAO, SpiroO‐QAO, SpiroOSO ‐QAO. A rigid molecular skeleton spiro structure as an intramolecular lock enables four to exhibit emissions. After full oxidization sulfur, band ‐QAO further narrowed, width at half maximum 32 nm, compared 43 nm sulfane‐decorated which attributed suppressed C─S bond‐length variation by introduction group. Nearly identical spectra SpiroO‐QAO suggest should be directly linked core maximize its function. Maximum external quantum efficiencies 30.8%, 30.3%, 29.2% are achieved SpiroS‐QAO‐based sensitized organic light‐emitting diodes highly efficient thermally activated delayed fluorescence assistant host. These results offer understanding embedded respect band.

Язык: 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, Год журнала: 2025, Номер unknown

Опубликована: Май 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.

Язык: 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, Год журнала: 2024, Номер 499, С. 155864 - 155864

Опубликована: Сен. 16, 2024

Язык: Английский

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SOGCN: Prediction of key properties of MR-TADF materials using graph convolutional neural networks

Chemical Engineering Journal, Год журнала: 2024, Номер 501, С. 157676 - 157676

Опубликована: Ноя. 14, 2024

Язык: Английский

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Efficient Narrowband Multiple Resonance Thermally Activated Delayed Fluorescent Emitters with Alleviated Efficiency Roll-Off via Steric Shielding and Heavy Atom Effect

The Journal of Physical Chemistry C, Год журнала: 2024, Номер 128(33), С. 13756 - 13762

Опубликована: Авг. 14, 2024

Organic light-emitting diodes (OLEDs) based on multiresonance-induced thermally activated delayed fluorescent (MR-TADF) materials are revolutionizing the field of organic electroluminescence and expected to be next-generation ultrahigh definition display technology. The rapid reverse intersystem crossing (RISC) process TADF emitter is crucial for achieving high-performance OLEDs with low-efficiency roll-off. Here, we present a novel B–N framework-based MR-TADF emitter, Cz-2PTz-BN, which exhibits narrow full width at half maxima 37 nm in toluene high photoluminescence quantum yield (PLQY) 93% doped film. introduced sulfur atoms Cz-2PTz-BN enhance its spin–orbital couplings (SOC) accelerate RISC process. corresponding OLED demonstrates maximum external efficiency (EQEmax) 28.7% low roll-off, maintaining EQEs 27.2 20.8% even brightnesses 100 1000 cd m–2 without sensitizer. These outcomes indicate promise this molecular design strategy obtain color purity efficiency.

Язык: Английский

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Boron‐Dipyrromethene Emitters with Strengthened Rigidity and Restricted Scissoring Vibration for High‐Performance OLEDs With Deep‐Red Narrowband Emission

Advanced Optical Materials, Год журнала: 2024, Номер unknown

Опубликована: Окт. 17, 2024

Abstract Organic light‐emitting diodes (OLEDs) using a simple solution‐processing approach have natural advantages in cost‐effective commercialization. However, solution‐processed deep‐red OLEDs are rarely reported due to the scarcity of efficient purely organic narrowband red emitters with commendable film‐forming capabilities. Herein, strategy is proposed develop molecules emission by expanding rigid conjugated frame block rotation α position boron‐dipyrromethene (BODIPY) core restricted twisting vibration. Furtherly, introducing moderate donor meso‐position BODIPY core, bathochromic‐shifted can be achieved without sacrificing narrow full‐width at half‐maximum (FWHM) increasing electron density whole molecule and repulsive force distal units suppress stretching/scissoring By employing developed BODIPY‐derived materials as terminal thermally activated delayed fluorescence material assistant host fabricate OLED devices, maximum external quantum efficiency 16.43% an peak 672 nm FWHM 28 nm. This work, according knowledge, represents best instance based on typical fluorescent emitters.

Язык: Английский

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Syntheses of multi-resonance frameworks towards narrowband organic light-emitting diodes

Chemical Communications, Год журнала: 2024, Номер unknown

Опубликована: Янв. 1, 2024

The synthetic strategies of multi-resonance frameworks are summarized, focusing on the means introducing various electron-withdrawing atoms/groups.

Язык: Английский

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Synergistic π‐Extension and Peripheral‐Locking of B/N‐Based Multi‐Resonance Framework Enables High‐Performance Pure‐Green Organic Light‐Emitting Diodes

Angewandte Chemie International Edition, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 7, 2024

Multi-resonance thermally activated delayed fluorescence (MR-TADF) emitters offer natural advantages for creating power-efficient, wide-color-gamut OLEDs. However, current green MR-TADF face challenges in simultaneously achieving high color purity and efficient reverse inter-system crossing (RISC), leading to suboptimal device performance. In this study, we propose a synergistic molecular design approach that combines π-extension peripheral locking address these challenges. This allows the construction of quadruple borylated not only deliver precisely tuned pure-green emission with narrow full width at half maximum (FWHM) 15 nm, but also exhibit close-to-unity quantum yield, rapid RISC, optimal horizontal dipole orientation. The resulting sensitizer-free OLED approaches BT.2020 standard CIE coordinates (0.18, 0.74) demonstrates impressive external efficiency (EQE) 36.6 % 31.8 1000 cd m

Язык: Английский

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

Advanced Optical Materials, Год журнала: 2024, Номер unknown

Опубликована: Дек. 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.

Язык: Английский

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