B‒N covalent bond-involved π-extension of multiple resonance emitters enables high-performance narrowband electroluminescence

National Science Review, Journal Year: 2024, Volume and Issue: 11(6)

Published: March 23, 2024

ABSTRACT Multi-boron-embedded multiple resonance thermally activated delayed fluorescence (MR-TADF) emitters show promise for achieving both high color-purity emission and exciton utilization efficiency. However, their development is often impeded by a limited synthetic scope excessive molecular weights, which challenge material acquisition organic light-emitting diode (OLED) fabrication vacuum deposition. Herein, we put forward B‒N covalent bond-involved π-extension strategy via post-functionalization of MR frameworks, leading to the generation high-order B/N-based motifs. The structurally electronically extended π-system not only enhances rigidity narrow linewidth but also promotes reverse intersystem crossing mitigate efficiency roll-off. As illustrated examples, ultra-narrowband sky-blue (full-width at half-maximum as small 8 nm in n-hexane) have been developed with multi-dimensional improvement photophysical properties compared precursor emitters, enables narrowband OLEDs external quantum efficiencies (EQEmax) up 42.6%, company alleviated decline brightness, representing best reported single-host OLEDs. success these highlights effectiveness our design advanced MR-TADF confirms extensive potential high-performance optoelectronic devices.

Language: Английский

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

Advanced Optical Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 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.

Language: Английский

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Regional Functionalization Molecular Design Strategy: A Key to Enhancing the Efficiency of Multi‐Resonance OLEDs

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(38)

Published: July 6, 2024

Herein, we propose a regional functionalization molecular design strategy that enables independent control of distinct pivotal parameters through different molecule segments. Three novel multiple resonances thermally activated delayed fluorescence (MR-TADF) emitters A-BN, DA-BN, and A-DBN, have been successfully synthesized by integrating highly rigid three-dimensional adamantane-containing spirofluorene units into the MR framework. These molecules form two distinctive functional parts: part 1 comprises boron-nitrogen (BN)-MR framework with adjacent benzene fluorene forming central luminescent core characterized an exceptionally planar geometry, allowing for narrow FWHM values; 2 includes peripheral mesitylene, benzene, adamantyl groups, creating unique "umbrella-like" conformation to mitigate intermolecular interactions suppress exciton annihilation. The resulting A-DBN exhibit remarkably values ranging from 18 14 nm near-unity photoluminescence quantum yields. Particularly, OLEDs based on DA-BN demonstrate outstanding efficiencies 35.0 % 34.3 %, as low 22 25 nm, respectively, effectively accomplishing integration high color purity device performance.

Language: Английский

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Efficient solution-processable OLEDs near BT.2020 red standard enabled by a multiresonant emitter

Science Bulletin, Journal Year: 2024, Volume and Issue: 69(19), P. 2983 - 2986

Published: Aug. 3, 2024

Language: Английский

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Design of Thermally Activated Delayed Fluorescence Materials: Transition from Carbonyl to Amide‐Based Acceptors

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: July 12, 2024

Benzophenone skeletons containing a carbonyl unit (O=C) have been widely used as electron acceptors in the thermally activated delayed fluorescence (TADF) materials. Herein, we present novel molecular design concept for TADF materials by transitioning from to an amide (O=C-N) skeleton acceptor. The unit, compared its counterpart, offers more stable electronic configuration. Leveraging this insight, developed series of high-performance molecules based on benzoyl carbazole and carbazoline acceptors. These exhibit exceptionally small singlet-triplet energy gaps pronounced aggregation-enhanced emission properties, achieving photoluminescence quantum yields neat films high 99 %. Consequently, these serve efficient emitters non-doped organic light-eimtting diodes (OLEDs), reaching maximum efficiency (EQE

Language: Английский

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Spirobifluorene-fused strategy enables pure-green multiple resonance emitters with low efficiency roll-off

Materials Horizons, Journal Year: 2024, Volume and Issue: 11(19), P. 4674 - 4680

Published: Jan. 1, 2024

The spiroannulation of multiple resonance core skeleton gives rise to pure-green emitters and superior electroluminescence performance with low efficiency roll-off.

Language: Английский

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喹喔啉并菲啰啉类热激活延迟荧光材料的合成及其发光性质

Acta Optica Sinica, Journal Year: 2025, Volume and Issue: 45(1), P. 0116001 - 0116001

Published: Jan. 1, 2025

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

Advanced Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 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.

Language: Английский

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A Novel Chrysene‐Anthracene Host Material for Enhanced Efficiency and Lifetime in Blue Fluorescent OLEDs

Advanced Optical Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 28, 2025

Abstract In this study, PAP‐1‐Ch is presented, a novel anthracene‐based host material, designed specifically for high‐efficiency and stable blue fluorescent organic light‐emitting diodes (OLEDs). The unique molecular architecture of integrates chrysene substituent anthracene, achieving an optimal balance between steric hindrance linearity. This plays critical role in minimizing π–π stacking, which effectively prevents fluorescence quenching while promoting favorable horizontal orientation up to 91.5% enhancing the photoluminescence quantum yield (PLQY) 93.1%, thereby significantly improving out‐coupling efficiency. Furthermore, finely tuned structure results superior charge carrier mobility more balanced electron/hole injection current. Devices fabricated with as material demonstrated remarkable performance metrics, color purity Commission Internationale de l'Eclairage (CIE) coordinates (0.136, 0.130), luminance efficiency 13.2 cd A −1 , maximum external ( EQE ) 12.6%, operational lifetime (LT 95 over 12 000 h at 100 m − 2 . These represent substantial advancement development high‐efficiency, OLEDs, paving way their application next generation high‐end displays.

Language: Английский

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

Communications Chemistry, Journal Year: 2025, Volume and Issue: 8(1)

Published: Feb. 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.

Language: Английский

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