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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Recent Advances in Narrow Emission Bandwidth Materials for Application in Organic Light‐Emitting Diodes

Advanced Optical Materials, Год журнала: 2025, Номер unknown

Опубликована: Фев. 21, 2025

Abstract The preparation of narrow emission bandwidth materials is crucial for the development advanced organic light‐emitting diodes (OLEDs). In this review article, state‐of‐the‐art methodologies used emitters with high color purity are summarized, and favorable design strategies rationally organized. Currently OLEDs have some issues, such as device stabilization that must be resolved, should also considered. Given recent exponential growth in number types narrowband emissive organometallic complexes exhibiting multiple‐resonance thermally activated delayed fluorescence metal‐to‐ligand charge transfer characteristics, there an urgent need to establish key technology descriptors purity. review, developments boron, fused indolocarbazole, carbonyl, phosphine oxide, exhibit spectra described, future directions advance performance devices suggested.

Язык: Английский

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Isomeric Pentagonal Fusion and π‐Expanding of Nitrogen/Carbonyl‐Containing Multi‐Resonant Emitters for High‐Performance and Narrowband Organic Electroluminescence

Advanced Functional Materials, Год журнала: 2025, Номер unknown

Опубликована: Фев. 26, 2025

Abstract Embedding nitrogen/carbonyl (N/C═O) units into rigid heterocyclic aromatic hydrocarbons creates novel multi‐resonant thermally activated delayed fluorescence (MR‐TADF) molecules. Nevertheless, the intrinsic short‐range charge transfer (SRCT) characteristics of N/C═O derivatives, as exemplified by quinolino[3,2,1‐ de ]acridine‐5,9‐dione (QAO), result in broad spectral bandwidths, posing challenging for achieving deep blue emission. Herein, a pentagonal cyclization and isomeric expansion strategy aimed is proposed at modulating SRCT characters molecular symmetry to further narrow bandwidths regulate excited‐state energy levels. By fusing two 8 H ‐indolo[3,2,1‐ ]acridin‐8‐one (IAO) skeletons via central phenyl segment that cyclizes nitrogen atoms, proof‐of‐concept emitters with reduced widths are developed. These achieved wide color tuning range from (439 nm) pure green (520 exhibited 17–24 nm (≈0.11 eV). The corresponding electroluminescence devices demonstrated bright deep‐blue, blue, emissions linewidths. Notably, sensitized deep‐blue/blue incorporating mTIAO pTIAO exceptional external quantum efficiencies 29.6% 34.4%, respectively, representing most efficient blue‐light derivatives reported date. Furthermore, index mTIAO, measured (0.147, 0.063), aligns perfectly National Television System Committee standard (0.15, 0.06).

Язык: Английский

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Blue Multiple‐Resonance Thermally Activated Delayed Fluorescence Materials

Advanced Optical Materials, Год журнала: 2025, Номер unknown

Опубликована: Фев. 8, 2025

Abstract Organic light‐emitting diodes (OLEDs) exhibit significant advantages in the fields of ultra‐high‐definition (UHD) displays and wearable devices. However, developing low‐cost, high‐efficiency, high‐purity blue emission materials remains a challenge for academia industry. While thermally activated delayed fluorescence (TADF) meet low‐cost manufacturing needs achieve 100% internal quantum efficiency, their charge‐transfer excited states lead to broad spectra that don't BT.2020 standard. Fortunately, multiple resonance (MR) strategy offers an effective solution creating TADF with high color purity. Through careful structural design precise tuning state energy levels, MR‐TADF can easily full‐width at half‐maximum (FWHM) less than 30 nm. Nevertheless, it still faces challenges, such as severe aggregation‐induced quenching efficiency roll‐off. Herein, this work overviews recent progress devices, introduce representative molecular strategies aimed suppressing concentration quenching, enhancing reverse intersystem crossing rates, achieving deep emission, which will aid future endeavors develop more efficient, stable devices suitable UHD display applications.

Язык: Английский

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Efficient non-doped blue electrofluorescence with electric field dependence of electron mobility

Chemical Engineering Journal, Год журнала: 2024, Номер unknown, С. 156905 - 156905

Опубликована: Окт. 1, 2024

Язык: Английский

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Carbonyl-nitrogen multi-resonance emitters for efficient OLEDs with high color purity

Communications Chemistry, Год журнала: 2025, Номер 8(1)

Опубликована: Фев. 4, 2025

Multi-resonance (MR) materials hold an intriguing feature of narrow emission spectra and have attracted considerable attention in the manufacture high-definition organic light-emitting diodes (OLEDs). However, majority MR are composed by a boron-nitrogen skeleton, which is unfavorable for expanding scope luminescent with to meet various application demands. In this work, we wish report new carbonyl-nitrogen (C = O/N) skeleton 5,12-dihydroquinolino[2,3-b]acridine-7,14-dione (QA), three tailored C O/N molecules synthesized fully characterized crystallography, thermal measurement, cyclic voltammetry, steady-state transient spectroscopy theoretical calculation. They show efficient green emissions full width at half maximum (FWHM) about 27 nm high photoluminescence quantum yields up 93% doped films. Efficient hyperfluorescence OLEDs fabricated using these as emitters, providing pure lights electroluminescence peaks 526‒538 nm, FWHMs 29‒33 excellent external efficiencies 29.48% small efficiency roll-offs. These results reveal that QA could be potential exploring molecules. possess spectra, desirable diodes, but most based on limited opportunities expand materials. Here, authors develop multi-resonance yields, further demonstrate their promise through fabrication OLEDs.

Язык: Английский

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Theoretical Study for Constructing Red Multiple-Resonance Thermally Activated Delayed Fluorescence Molecules with Narrowband Emission by Donor Engineering Strategy

Chinese Journal of Physics, Год журнала: 2025, Номер unknown

Опубликована: Фев. 1, 2025

Язык: Английский

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Engineering Nitrogen/Carbonyl MR‐TADF Emitters: Spiro‐Lock and Tert‐Butyl Synergy in Narrowband Blue Emission

Small, Год журнала: 2025, Номер unknown

Опубликована: Март 30, 2025

Abstract Multi‐resonance thermally activated delayed fluorescence (MR‐TADF) emitters with rigid planar structures are promising for their exceptional color purity and outstanding device efficiency. However, as an important MR unit, rigidly interlocked nitrogen/carbonyl‐based blue materials often face challenges like spectral broadening, red‐shifting, reduced efficiency compared to nitrogen/boron system. Herein, a peripheral modification strategy incorporating tert ‐butyl groups via spiro‐lock framework is used synthesize four molecules: QAO‐TF, TQAO‐TF, TQAO‐F, TSOQ. The structure solidifies the molecular framework, narrows emission bandwidth, elevates photoluminescence quantum yield over 96%. Meanwhile, introduce steric hindrance, isolating luminescent core suppressing intermolecular interactions in solid state, thereby improving while maintaining narrowband emission. Notably, TQAO‐F shows electroluminescence peak at 476 nm 25 full width half maximum (FWHM) external (EQE) of 31.7%. TSOQ, its oxygen‐induced charge effect, achieves pure FWHM 20 nm, surpassing 30% EQE without sensitizers. This overall performance suggests potential rival classic

Язык: Английский

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Recent Progress in Molecular Design of Boron/Nitrogen‐Based Multi‐Resonance Materials for Narrowband Organic Light‐Emitting Diodes

Advanced Optical Materials, Год журнала: 2025, Номер unknown

Опубликована: Апрель 11, 2025

Abstract Luminescent boron‐nitrogen (BN)‐type multi‐resonance (MR) materials have been first reported by Hatakeyama and co‐workers in 2016. BN‐type MR attracted a lot of attention, because their unique photophysical properties, including narrowband emissions, high photoluminescent quantum yields, thermally activated delayed fluorescent (TADF) properties. MR‐TADF are considered as the next‐generation luminescent for efficient, stable, narrow‐emission organic light‐emitting diodes (OLEDs). Herein, comprehensive review recent progress is provided highlighting structures, device performances. Moreover, future perspective development will be discussed.

Язык: Английский

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Intramolecular Hydrogen Bond Modulated the Formation of Exciplex for Highly Efficient Organic Light-Emitting Diodes

The Journal of Physical Chemistry Letters, Год журнала: 2025, Номер unknown, С. 4277 - 4284

Опубликована: Апрель 22, 2025

Although exciplexes with thermally activated delayed fluorescence (TADF) properties have been applied in high-efficiency organic electroluminescent devices, the development of has hindered due to limited material systems and unclear formation mechanisms. Inspired by unusual exciplex emission discovered pyridine solution 2,12-di-tert-butyl-5,9-dithia-13b-boranaphtho[3,2,1-de]anthracene (TSBA) this work, mechanism based on two groups pyridine-based derivative isomeric acceptors 26DCzPPy, 35DCzPPy B2PyPB, B3PyPB B4PyPB was explored accordingly. The difference position substituted can effectively regulate intramolecular N···H hydrogen bonds, which further affects their interaction electron-donating unit TSBA through a conformational locking effect-induced topological rigidification molecule, ultimately determining exciplex. Based mechanism, 35DCzPPy, acceptors, combined donor, display TADF as expected. Among these, 35DCzPPy:TSBA shows excellent property high photoluminescent quantum yield reaching 78%, corresponding device achieves external efficiency 18.72% along small roll-off. An in-depth investigation into influence mechanisms interactions construction work will provide crucial theoretical guidance design strategies for developing novel, highly efficient materials.

Язык: Английский

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