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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B‐N Covalent Bond Embedded Double Hetero‐[n]helicenes for Pure Red Narrowband Circularly Polarized Electroluminescence with High Efficiency and Stability

Advanced Materials, Год журнала: 2023, Номер 36(5)

Опубликована: Сен. 12, 2023

Chiral B/N embedded multi-resonance (MR) emitters open a new paradigm of circularly polarized (CP) organic light-emitting diodes (OLEDs) owing to their unique narrowband spectra. However, pure-red CP-MR and devices remain exclusive in literature. Herein, by introducing B-N covalent bond lower the electron-withdrawing ability para-positioned B-π-B motif, first pair double hetero-[n]helicenes (n = 6 7) emitter peaking 617 nm with small full-width at half-maximum 38 high photoluminescence quantum yield ≈100% toluene is developed. The intense mirror-image CP light produced enantiomers characterized dissymmetry factors (g

Язык: Английский

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Nitrogen‐Embedding Strategy for Short‐Range Charge Transfer Excited States and Efficient Narrowband Deep‐Blue Organic Light Emitting Diodes

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(35)

Опубликована: Июнь 3, 2024

The development of deep-blue organic light-emitting diodes (OLEDs) featuring high efficiency and narrowband emission is great importance for ultrahigh-definition displays with wide color gamut. Herein, based on the nitrogen-embedding strategy modifying short range charge transfer excited state energies multi-resonance (MR) thermally activated delayed fluorescence (TADF) emitters, we introduce one or two nitrogen atoms into central benzene ring a versatile boron-embedded 1,3-bis(carbazol-9-yl)benzene skeleton. This approach resulted in stabilization highest occupied molecular orbital energy levels formation intramolecular hydrogen bonds, thus systematic hypsochromic shifts narrowing spectra. In toluene solution, heterocyclic-based MR-TADF molecules, Py-BN Pm-BN, exhibit emissions photoluminescence quantum yields 93 % 94 %, narrow full width at half maximum 14 13 nm, respectively. A hyperfluorescent OLED exhibited external 27.7 desired purity Commission Internationale de L'Eclairage (CIE) coordinates (0.150, 0.052). These results demonstrate significant potential deep blue emitters.

Язык: Английский

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Efficient Deep‐Blue Multiple‐Resonance Emitters Based on Azepine‐Decorated ν‐DABNA for CIE_y below 0.06

Advanced Materials, Год журнала: 2024, Номер 36(30)

Опубликована: Май 2, 2024

Abstract Ultrapure deep‐blue emitters are in high demand for organic light‐emitting diodes (OLEDs). Although color coordinates serve as straightforward parameters assessing purity, precise control over the maximum wavelength and full‐width at half‐maximum is necessary to optimize OLED performance, including luminance efficiency luminous efficacy. Multiple‐resonance (MR) promising candidates achieving ideal luminescence properties; consequently, a wide variety of MR frameworks have been developed. However, most these experience displacement from color, which limits their practical applicability. Therefore, molecular design that compatible with modulating energy levels output particularly valuable. Here, it demonstrated azepine donor unit induces an appropriate blue‐shift emission while maintaining efficient characteristics, photoluminescence quantum yield, narrow emission, fast reverse intersystem crossing rate. OLEDs using newly developed based on ν ‐DABNA framework simultaneously exhibit ≈30%, efficacy ≈20 lm W −1 , exceptional purity Commission Internationale de l’Éclairage low (0.14, 0.06), notably operational stability. These results demonstrate unprecedentedly compared those observed previously reported emitters.

Язык: Английский

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Excited‐State Engineering Enables Efficient Deep‐Blue Light‐Emitting Diodes Exhibiting BT.2020 Color Gamut

Advanced Materials, Год журнала: 2024, Номер 36(31)

Опубликована: Апрель 10, 2024

Organic luminescent materials that exhibit thermally activated delayed fluorescence (TADF) can convert non-emissive triplet excitons into emissive singlet states through a reverse intersystem crossing (RISC) process. Therefore, they have tremendous potential for applications in organic light-emitting diodes (OLEDs). However, with the development of ultra-high definition 4K/8K display technologies, designing efficient deep-blue TADF to achieve Commission Internationale de l'Éclairage (CIE) coordinates fulfilling BT.2020 remains significant challenge. Here, an effective approach is proposed design molecules based on hybrid long- and short-range charge-transfer by incorporation multiple donor moieties organoboron resonance acceptors. The resulting molecule exhibits emission at 414 nm full width half maximum (FWHM) 29 nm, together thousand-fold increase RISC rate. OLEDs champion material record external quantum efficiency (EQE) 22.8% CIE (0.163, 0.046), approaching blue standard. Moreover, TADF-assisted devices employing designed as sensitizer exceptional EQE 33.1%. This work thus provides blueprint future emitters, representing important milestone towards meeting color gamut standard BT.2020.

Язык: Английский

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Stepwise Toward Pure Blue Organic Light‐Emitting Diodes by Synergetically Locking and Shielding Carbonyl/Nitrogen‐Based MR‐TADF Emitters

Advanced Science, Год журнала: 2024, Номер 11(28)

Опубликована: Май 5, 2024

Deep-blue multi-resonance (MR) emitters with stable and narrow full-width-at-half-maximum (FWHM) are of great importance for widening the color gamut organic light-emitting diodes (OLEDs). However, most planar MR vulnerable to intermolecular interactions from both host guest, causing spectral broadening exciton quenching in thin films. Their emission solid state is environmentally sensitive, purity often inferior that solutions. Herein, a molecular design strategy presented simultaneously narrows FWHM suppresses by combining intramolecular locking peripheral shielding within carbonyl/nitrogen-based core. Intramolecularly bears narrower 2,10-dimethyl-12,12-diphenyl-4H-benzo[9,1]quinolizino[3,4,5,6,7-defg]acridine-4,8(12H)-dione solution further peripheral-shielding groups, deep-blue emitter (12,12-diphenyl-2,10-bis(9-phenyl-9H-fluoren-9-yl)-4H-benzo[9,1]quinolizino[3,4,5,6,7-defg]acridine-4,8(12H)-dione, DPQAO-F) exhibits ultra-pure (c.a., 24 nm) minimal variations (∆FWHM ≤ 3 films over wide doping range. An OLED based on DPQAO-F presents maximum external quantum efficiency (EQE

Язык: Английский

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“Core–Shell” Wave Function Modulation in Organic Narrowband Emitters

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(27), С. 18331 - 18340

Опубликована: Июнь 20, 2024

Efficient red–green–blue primary luminescence with an extraordinarily narrow band and durability is crucial for advanced display applications. Recently, the emergence of multiple-resonance (MR) from short-range atomic interactions has been shown to induce extremely spectral widths in pure organic emitters. However, achieving wide-range color tuning without compromising purity remains a persistent challenge MR Herein, concept electronic donor/acceptor "core–shell" modulation proposed within boron/nitrogen (B/N) skeleton, enabling rational utilization intramolecular charge transfer facilitate wavelength shift. The dense B atoms localized at center molecule effectively compress electron density stabilize lowest unoccupied molecular orbital wave function. This electron-withdrawing core embedded peripheral electron-donating atoms. Consequently, doping single atom into deep-blue framework led profound bathochromic shift 447 624 nm (∼0.8 eV) while maintaining width 0.10 eV this pure-red emitter. Notably, light-emitting diodes assisted by thermally activated delayed fluorescence molecules achieved superb electroluminescent stability, LT99 (99% initial luminance) exceeding 400 h luminance 1000 cd m–2, approaching commercial-level performance assistance phosphors.

Язык: Английский

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The degradation mechanism of multi-resonance thermally activated delayed fluorescence materials

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Янв. 4, 2025

1,4-Azaborine-based arenes are promising electroluminescent emitters with thermally activated delayed fluorescence (TADF), offering narrow emission spectra and high quantum yields due to a multi-resonance (MR) effect. However, their practical application is constrained by limited operational stability. This study investigates the degradation mechanism of MR-TADF molecules. Electroluminescent devices incorporating these compounds display varied lifetimes, uncorrelated excitonic stability or external efficiency roll-off. Bulk electrolysis reveals significant instability in radical cationic forms compounds, device lifetime linked Faradaic yield oxidation. Comprehensive chemical analyses corroborate that byproducts originated from intramolecular cyclization cation, followed hydrogen atom transfer. The further supported enhanced observed deuterated emitter, attributed secondary kinetic isotope These findings provide insights into stabilizing effects deuteration mechanism-driven strategies for designing improved longevity. often constrains application. Here, authors report direct correlation between oxidative emitter

Язык: Английский

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Exploring Efficient Blue TADF Materials with Ultrafast Bipolar Charge Transport for High‐Efficiency Thick‐Layer OLEDs

Advanced Functional Materials, Год журнала: 2024, Номер 34(30)

Опубликована: Март 26, 2024

Abstract Achieving strong solid‐state photoluminescence and fast charge transport simultaneously for organic molecules is of significant importance but challenging because the trade‐off between these properties. Herein, two tailored blue luminescent constructed with ring‐fused carbonyl‐containing electron acceptors spiro‐acridine donors are developed. Owing to ordered long‐range molecular alignment proper interaction energies, their neat films exhibit ultrafast bipolar delayed fluorescence high quantum yields short lifetimes. In doped light‐emitting diodes (OLEDs), both display eminent electroluminescence performances excellent external efficiencies (EQEs) 40.6%. They also brilliant lights record‐beating EQEs 30.2% in non‐doped thin‐layer OLEDs, more importantly, high‐performance simplified thick‐layer OLEDs achieved, rendering lowered driving voltages, best 23.0% tiny efficiency roll‐offs. addition, using them as sensitizers, remarkable 40.1% 23.2% ultrasmall roll‐offs realized hyperfluorescence respectively. The operational lifetimes obviously elongated matter devices or devices. This work provides promising candidates efficient opens a new avenue toward simultaneously.

Язык: Английский

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Stereo effects for efficient synthesis of orange-red multiple resonance emitters centered on a pyridine ring

Chemical Science, Год журнала: 2024, Номер 15(9), С. 3148 - 3154

Опубликована: Янв. 1, 2024

Despite theoretical difficulties, we herein demonstrate an effective strategy for the inaugural synthesis of orange-red multiple resonance (MR) emitter centered on a pyridine ring

Язык: Английский

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