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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Key requirements for ultraefficient sensitization in hyperfluorescence organic light-emitting diodes

Nature Photonics, Год журнала: 2024, Номер 18(6), С. 554 - 561

Опубликована: Фев. 13, 2024

Abstract Blue organic light-emitting diode (OLED) technology requires further advancements, and hyperfluorescent (HF) OLEDs have emerged as a promising solution to address stability colour-purity concerns. A key factor influencing the performance of HF-OLEDs is Förster resonance energy transfer (FRET). Here we investigate FRET mechanism in blue using contrasting thermally activated delayed fluorescence (TADF) sensitizers. We demonstrate that molecular structure sensitizer profoundly impacts efficiency, exemplified by spiro-linked TADF molecule ACRSA, which suppresses dihedral-angle inhomogeneity any lower-energy conformers exhibit minimal terminal emitter. Consequently, efficiency can be optimized nearly 100%. Further, how properties near-ideal diverge from ideal emitters. As result, utilizing greenish remarkable tripling external quantum (~30%) compared with non-HF devices. This new understanding opens avenues for design, indicating green sensitizers efficiently pump emitters, thereby reducing device exciton energies improving OLED stability.

Язык: Английский

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Tailoring Extremely Narrow FWHM in Hypsochromic and Bathochromic Shift of Polycyclo‐Heteraborin MR‐TADF Materials for High‐Performance OLEDs

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(32)

Опубликована: Июнь 10, 2023

Developing double boron-based emitters with extremely narrow band spectrum and high efficiency in organic light-emitting diodes (OLEDs) is crucial challenging. Herein, we report two materials, NO-DBMR Cz-DBMR, hinge on polycyclic heteraborin skeletons based role-play of the highest occupied molecular orbital (HOMO) energy levels. The contains an oxygen atom, whereas Cz-DBMR has a carbazole core boron-embedded ν-DABNA structure. synthesized materials resulted unsymmetrical pattern for surprisingly symmetrical Cz-DBMR. Consequently, both showed full width at half maximum (FWHM) 14 nm hypsochromic (pure blue) bathochromic (Bluish green) shifted emission without losing their color fidelity. Furthermore, show photoluminescence quantum yield (PLQY) over 82 %, small singlet-triplet gap (ΔEST ) 0.04 eV, resulting reverse intersystem crossing process (kRISC 105 s-1 . Due to efficient thermally activated delayed fluorescence (TADF) characteristics, fabricated OLEDs these heteraborins manifested external (EQEmax 33.7 29.8 % respectively. This first work reported this type strategy achieving emissions similar skeleton.

Язык: Английский

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Highly efficient pure-blue organic light-emitting diodes based on rationally designed heterocyclic phenophosphazinine-containing emitters

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Июль 22, 2024

Abstract Multi-resonance thermally activated delayed fluorophores have been actively studied for high-resolution photonic applications due to their exceptional color purity. However, these compounds encounter challenges associated with the inefficient spin-flip process, compromising device performance. Herein, we report two pure-blue emitters based on an organoboron multi-resonance core, incorporating a conformationally flexible donor, 10-phenyl-5 H -phenophosphazinine 10-oxide (or sulfide). This design concept selectively modifies orbital type of high-lying excited states charge transfer configuration while simultaneously providing necessary conformational freedom enhance density without sacrificing We show that different embedded phosphorus motifs (phosphine oxide/sulfide) donor can finely tune electronic structure and freedom, resulting in accelerated process through intense spin-vibronic coupling, achieving over 20-fold increase reverse intersystem crossing rate compared parent emitter. Utilizing emitters, achieve high-performance organic light-emitting diodes, showcasing top-tier external quantum efficiency 37.6% reduced roll-offs. proposed strategy not only conventional notion electron-donors are undesirable constructing narrowband but also offer pathway designing efficient narrow-spectrum blue diodes.

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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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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Marching Toward Long‐Wavelength Narrowband Emissive Multi‐Resonance Delayed Fluorescence Emitters for Organic Light Emitting Diodes

Advanced Optical Materials, Год журнала: 2023, Номер 11(22)

Опубликована: Окт. 4, 2023

Abstract Over the past decade, thermally activated delayed fluorescence (TADF) emitters have garnered tremendous impetus because of their ability to harvest 100% excitons for light emission in organic emitting diodes (OLEDs). However, despite superior external quantum efficiencies (> 35%), broad spectra with associated full‐width‐at‐half maximum (FWHM > 70 nm) present a limiting factor that must be solved. Recently, multiple‐resonance TADF (MR‐TADF) materials based on heteroatom doped polyaromatic hydrocarbons gained astonishing attention owing remarkable narrowband < 30 nm). majority reported MR‐TADF falls blue/green region, which inevitably jeopardizes application full‐color OLEDs. Therefore, there is an urgent need develop new molecular designs expanding color‐gamut emitters, i.e., λ em 550 nm without compromising emission. To best current knowledge, no detailed reviews focusing different design strategies producing long‐wavelength been date. this end, review highlighting recent advances constructing presented, and photophysics OLED performance discussed. Finally, status future prospects are

Язык: Английский

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Secondary donor-acceptor group enable efficient pure green organic light-emitting devices based on multi-resonance TADF emitters

Chemical Engineering Journal, Год журнала: 2024, Номер 481, С. 148794 - 148794

Опубликована: Янв. 14, 2024

Язык: Английский

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Rigidification with indolocarbazole and molecular orbitals regulation by peripheral donation towards pure green polycyclo-heteraborin MR-TADF scaffolds for stable narrowband OLEDs

Chemical Engineering Journal, Год журнала: 2024, Номер 481, С. 148781 - 148781

Опубликована: Янв. 19, 2024

Язык: Английский

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Forthcoming hyperfluorescence display technology: relevant factors to achieve high-performance stable organic light emitting diodes

Frontiers in Chemistry, Год журнала: 2023, Номер 11

Опубликована: Июнь 12, 2023

Over the decade, there have been developments in purely organic thermally activated delayed fluorescent (TADF) materials for light-emitting diodes (OLEDs). However, achieving narrow full width at half maximum (FWHM) and high external quantum efficiency (EQE) is crucial real display industries. To overcome these hurdles, hyperfluorescence (HF) technology was proposed next-generation OLEDs. In this technology, TADF material considered a sensitizing host, so-called sensitized host (TSH), use of triplet excitons via reverse intersystem crossing (RISC) pathway. Since most show bipolar characteristics, electrically generated singlet exciton energies can be transported to final emitter (FE) through Förster resonance energy transfer (FRET) rather than Dexter (DET). This mechanism possible from S 1 state TSH dopant (FD) as long-range transfer. Considering this, some reports are available based on OLEDs, but detailed analysis highly efficient stable devices commercialization unclear. So herein, we reviewed relevant factors recent advancements build system. The include an spectral overlapping, requirements, electroluminescence study exciplex polarity system, shielding effect, DET suppression, FD orientation. Furthermore, outlook future positives with new directions were discussed high-performance

Язык: Английский

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