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

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(3), P. 1624 - 1692

Published: Jan. 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.

Language: Английский

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Synergetic Modulation of Steric Hindrance and Excited State for Anti‐Quenching and Fast Spin‐Flip Multi‐Resonance Thermally Activated Delayed Fluorophore

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(16)

Published: Feb. 8, 2024

Multi-resonance thermally activated delayed fluorescence (MR-TADF) materials hold great promise for advanced high-resolution organic light-emitting diode (OLED) displays. However, persistent challenges, such as severe aggregation-caused quenching (ACQ) and slow spin-flip, hinder their optimal performance. We propose a synergetic steric-hindrance excited-state modulation strategy MR-TADF emitters, which is demonstrated by two blue IDAD-BNCz TIDAD-BNCz, bearing sterically demanding 8,8-diphenyl-8H-indolo[3,2,1-de]acridine (IDAD) 3,6-di-tert-butyl-8,8-diphenyl-8H-indolo[3,2,1-de]acridine (TIDAD), respectively. These rigid bulky IDAD/TIDAD moieties, with appropriate electron-donating capabilities, not only effectively mitigate ACQ, ensuring efficient luminescence across broad range of dopant concentrations, but also induce high-lying charge-transfer excited states that facilitate triplet-to-singlet spin-flip without causing undesired emission redshift or spectral broadening. Consequently, implementation high doping level resulted in highly narrowband electroluminescence, featuring remarkable full-width at half-maximum 34 nm record-setting external quantum efficiencies 34.3 % 31.8 maximum 100 cd m

Language: Английский

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Acceleration of reverse intersystem crossing in multi-resonance TADF emitter

Chem, Journal Year: 2024, Volume and Issue: 10(5), P. 1485 - 1501

Published: Feb. 15, 2024

Language: Английский

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

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: July 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.

Language: Английский

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

Advanced Materials, Journal Year: 2024, Volume and Issue: 36(31)

Published: April 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.

Language: Английский

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

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(27), P. 18331 - 18340

Published: June 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.

Language: Английский

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Purely organic room-temperature phosphorescence sensitizers for highly efficient hyperfluorescence OLEDs

Science Advances, Journal Year: 2025, Volume and Issue: 11(12)

Published: March 21, 2025

Multiresonance thermally activated delayed fluorescence (MR-TADF) emitters are promising candidates for organic light-emitting diodes (OLEDs) with high color quality. However, in most cases, noble metal–containing phosphors required as sensitizers MR-TADF to improve their electroluminescence (EL) performances, which may lead cost and environmental pollution. Herein, an efficient purely room-temperature phosphorescence (RTP) material, 3,2-PIC-TXT, fast radiation is developed. It not only exhibits impressive EL performances emitter outstanding external quantum efficiency (EQE) of 33.2%, higher than that Ir(ppy) 3 (25.2%), but also functions remarkably a sensitizer green (BN2, tCzphB-Ph, tCzphB-Fl). The hyperfluorescence OLEDs using 3,2-PIC-TXT provide ultrahigh EQEs 40.9 43.8%, superior those based on (37.0 38.0%), along superb purity excellent operational stability. These the best devices RTP materials reported so far.

Language: Английский

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Regulation of Multiple Resonance Delayed Fluorescence via Through‐Space Charge Transfer Excited State towards High‐Efficiency and Stable Narrowband Electroluminescence

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(49)

Published: Oct. 18, 2023

B- and N-embedded multiple resonance (MR) type thermally activated delayed fluorescence (TADF) emitters usually suffer from slow reverse intersystem crossing (RISC) process aggregation-caused emission quenching. Here, we report the design of a sandwich structure by placing B-N MR core between two electron-donating moieties, inducing through-space charge transfer (TSCT) states. The proper adjusting energy levels brings about 10-fold higher RISC rate in comparison with parent molecule. In meantime, high photoluminescence quantum yield 91 % good color purity were maintained. Organic light-emitting diodes based on new emitter achieved maximum external efficiency 31.7 small roll-offs at brightness. High device efficiencies also obtained for wide range doping concentrations up to 20 wt thanks steric shielding core. A operational stability LT95 85.2 h has been revealed. dual electronic effects resulting introduction TSCT state offer an effective molecular address critical challenges MR-TADF emitters.

Language: Английский

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Recent progress in multi-resonance thermally activated delayed fluorescence emitters with an efficient reverse intersystem crossing process

Chemical Communications, Journal Year: 2023, Volume and Issue: 60(9), P. 1089 - 1099

Published: Dec. 21, 2023

Multi-resonance thermally activated delayed fluorescence (MR-TADF) emitters have become an active research topic at the forefront of organic light-emitting diodes (OLEDs) owing to their excellent photophysical properties such as high efficiency and narrow emission characteristics. However, MR-TADF materials always exhibit slow reverse intersystem crossing rates (

Language: Английский

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