Highly Efficient Asymmetric Multiple Resonance Thermally Activated Delayed Fluorescence Emitter with EQE of 32.8 % and Extremely Low Efficiency Roll‐Off

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(14)

Опубликована: Фев. 1, 2022

Multiple resonance thermally activated delayed fluorescence (MR-TADF) emitters show great potentials for high color purity organic light-emitting diodes (OLEDs). However, the simultaneous realization of photoluminescence quantum yield (PLQY) and reverse intersystem crossing rate (kRISC ) is still a formidable challenge. Herein, novel asymmetric MR-TADF emitter (2Cz-PTZ-BN) designed that fully inherits PLQY large kRISC values properly selected parent molecules. The resonating extended π-skeleton with peripheral protection can achieve 96 % fast above 1.0×105 s-1 , boost performance corresponding pure green devices an outstanding external efficiency (EQE) up to 32.8 without utilizing any sensitizing hosts. Remarkably, device sufficiently maintains EQE exceeding 23 at luminance 1000 cd m-2 representing highest value reported materials same luminescence.

Язык: Английский

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Achieving 37.1% Green Electroluminescent Efficiency and 0.09 eV Full Width at Half Maximum Based on a Ternary Boron‐Oxygen‐Nitrogen Embedded Polycyclic Aromatic System

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(23)

Опубликована: Март 18, 2022

Abstract Herein, a ternary boron‐oxygen‐nitrogen embedded polycyclic aromatic hydrocarbon with multiple resonance thermally activated delayed fluorescence (MR‐TADF), namely DBNO, is developed by adopting the para boron‐π‐boron and oxygen‐π‐oxygen strategy. The designed molecule presents vivid green emission high photoluminescence quantum yield (96 %) an extremely narrow full width at half maximum (FWHM) of 19 nm/0.09 eV, which surpasses all previously reported TADF emitters to date. In addition, long molecular structure along transition dipole moment direction endows it horizontal emitting ratio 96 %. organic light‐emitting diode (OLED) based on DBNO reveals narrowband peak 504 nm FWHM 24 nm/0.12 eV. Particularly, significantly improved device performance achieved TADF‐sensitization (hyperfluorescence) mechanism, presenting 27 external efficiency (EQE) 37.1

Язык: Английский

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Organoboron-based multiple-resonance emitters: synthesis, structure–property correlations, and prospects

Chemical Society Reviews, Год журнала: 2024, Номер 53(3), С. 1624 - 1692

Опубликована: Янв. 1, 2024

This review highlights organoboron-based multiple-resonance compounds’ synthetic strategies classified as one-pot borylation, one-shot and late-stage functionalisation, explores material structure–photophysical property correlations.

Язык: Английский

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Aggregation‐induced emission: Red and near‐infrared organic light‐emitting diodes

SmartMat, Год журнала: 2021, Номер 2(3), С. 326 - 346

Опубликована: Авг. 27, 2021

Abstract Red and near‐infrared (NIR) organic light‐emitting diodes (OLED) have gained remarkable interest due to their numerous applications. However, the construction of highly emissive emitters is hampered by energy‐gap law aggregation‐caused quenching (ACQ) effect. Whereas, aggregation‐induced emission (AIE) materials could avoid undesirable ACQ effect emit bright light in aggregated state, which one class most promising fabricate high‐performance OLED with a high external quantum efficiency low roll‐off. This review summarizes recent advances red NIR AIE property, including traditional fluorescence, thermally activated delayed hybridized local charge transfer compounds. Meanwhile, emphasis attention paid molecular design principles, as well structure‐photophysical characteristics. We also briefly further outlook challenges perspective luminogens.

Язык: Английский

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Multiple‐Resonance‐Induced Thermally Activated Delayed Fluorescence Materials Based on Indolo[3,2,1‐jk]carbazole with an Efficient Narrowband Pure‐Green Electroluminescence

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(41)

Опубликована: Авг. 19, 2022

Herein, we report two multiple-resonance thermally activated delayed fluorescence emitters (VTCzBN and TCz-VTCzBN) based on indolo[3,2,1-jk]carbazole unit boron-nitrogen skeletons, whose emissions peaking at 496 521 nm with full width half maximum of 34 29 nm, respectively. Meanwhile, fast rate constants reverse intersystem crossing above 106 s-1 are obtained due to small singlet-triplet energy gaps large spin-orbital coupling values. Notably, planar molecular structures along the transition dipole moment direction endow them high horizontal emitting ratios up 94 %. Consequently, corresponding organic light-emitting diodes (OLEDs) show external quantum efficiencies 31.7 % 32.2 %, Particularly, OLED TCz-VTCzBN display ultra-pure green emission Commission Internationale de l'Eclairage coordinates (0.22, 0.71), consistent standard National Television System Committee.

Язык: Английский

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Chiral Multi‐Resonance TADF Emitters Exhibiting Narrowband Circularly Polarized Electroluminescence with an EQE of 37.2 %

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(30)

Опубликована: Май 10, 2022

Highly efficient circularly polarized luminescence (CPL) emitters with narrowband emission remain a formidable challenge for OLEDs (CP-OLEDs). Here, promising strategy developing chiral concurrently featuring multi-resonance thermally activated delayed fluorescence (MR-TADF) and electroluminescence (CPEL) is demonstrated by the integration of molecular rigidity, central chirality MR effect. A pair green denoted as (R)-BN-MeIAc (S)-BN-MeIAc designed. Benefited rigid quasi-planar MR-framework, enantiomers not only display mirror-image CPL spectra, but also exhibit TADF properties high photoluminescence quantum yield 96 %, narrow FWHM 30 nm, horizontal dipole orientation 90 % in doped film. Consequently, enantiomer-based CP-OLEDs achieved excellent external efficiencies 37.2 very low efficiency roll-off, representing highest device all reported CP-OLEDs.

Язык: Английский

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A Chiral Dual‐Core Organoboron Structure Realizes Dual‐Channel Enhanced Ultrapure Blue Emission and Highly Efficient Circularly Polarized Electroluminescence

Advanced Materials, Год журнала: 2022, Номер 34(36)

Опубликована: Июль 15, 2022

The realization of luminescent materials with narrowband and circularly polarized luminescence (CPL) is great significance for the development future optical photonic devices. Herein, through a steric-hindrance-assisted dual-core strategy, two pairs chiral multiple resonance thermally activated delayed fluorescence (MR-TADF) (R/S-DOBN R/S-DOBNT) are directly constructed by bonding organoboron MR-TADF monocores (SOBN SOBNT) carbazole/3,6-di-tert-butyl-9H-carbazole phenol derivative as donors, realizing obvious CPL emissions. Furthermore, effect in prepared R/S-DOBN R/S-DOBNT increases transition oscillator strength times more than that monocore structure, while maintaining ultrapure blue emissions peaking at 453 459 nm narrower full-width half-maximum 21 reorganization energy reduction. organic light-emitting diodes based on enantiomers exhibit emission Commission Internationale de L'Eclairage (CIE) coordinates (0.14, 0.10) (0.13, 0.12), high maximum external quantum efficiencies 23.9% 25.6%, electroluminescence dissymmetry factors (|gEL |) ≈ 10-3 .

Язык: Английский

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Solution‐Processable Pure‐Red Multiple Resonance‐induced Thermally Activated Delayed Fluorescence Emitter for Organic Light‐Emitting Diode with External Quantum Efficiency over 20 %

Angewandte Chemie International Edition, Год журнала: 2022, Номер 62(7)

Опубликована: Дек. 13, 2022

Abstract Developing solution‐processable red organic light‐emitting diodes (OLEDs) with high color purity and efficiency based on multiple resonance thermally activated delayed fluorescence (MR‐TADF) is a formidable challenge. Herein, by introducing auxiliary electron donor acceptor moieties into the highest occupied molecular orbital (HOMO) lowest unoccupied (LUMO) distributed positions of skeleton simultaneously, an effective strategy to obtain MR‐TADF emitters was represented. The proof‐of‐the‐concept molecule BN‐R exhibits narrowband pure‐red emission at 624 nm, luminous 94 % narrow bandwidth 46 nm. Notably, fabricated OLED state‐of‐the‐art external quantum over 20 Commission Internationale de I’Éclairage coordinates (0.663, 0.337) long operational lifetime (LT 50 ) 1088 hours initial luminance 1000 cd m −2 .

Язык: Английский

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Sequential Multiple Borylation Toward an Ultrapure Green Thermally Activated Delayed Fluorescence Material

Journal of the American Chemical Society, Год журнала: 2022, Номер 145(3), С. 1505 - 1511

Опубликована: Дек. 22, 2022

Multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters have emerged as an important component of organic light-emitting diodes (OLEDs) because their narrowband emission and high exciton utilization efficiency. However, the chemical space MR-TADF remains mostly unexplored lack suitable synthetic protocols. Herein, we demonstrate a sequential multiple borylation reaction that provides new synthetically accessible space. ω-DABNA, proof-of-concept material, exhibited green TADF with full width at half-maximum 22 nm small singlet-triplet energy gap 13 meV. The OLED employing it emitter electroluminescence 512 nm, Commission International de l'Éclairage coordinates (0.13, 0.73) external quantum efficiency (EQE) 31.1%. Moreover, device showed minimum roll-off, EQE 29.4% 1000 cd m-2.

Язык: Английский

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Versatile boron‐based thermally activated delayed fluorescence materials for organic light‐emitting diodes

Aggregate, Год журнала: 2022, Номер 3(5)

Опубликована: Март 3, 2022

Abstract During the last few years, organoboron‐based thermally activated delayed fluorescence (TADF) materials have received extensive attention in optoelectronic area, owing to unique electronegativity of boron atom. Herein, many research progress TADF for organic devices is summarized. This review comprehensively documents according emission colors from blue red‐near‐infrared (red‐NIR), covering molecular design strategies, photophysical properties, and performance light‐emitting diodes (OLEDs). The current future challenges this fast‐growing fields are reviewed systematically, providing instructive guidance on high‐performance TADF‐OLEDs.

Язык: Английский

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