Construction of Hybrid Long- and Short-Range Charge Transfer Excitations for High-Performance Deep-Blue Electroluminescence with CIEy < 0.04 and EQE > 35% DOI

Jibiao Jin,

Mei Chen, He Jiang

et al.

ACS Materials Letters, Journal Year: 2024, Volume and Issue: unknown, P. 3246 - 3253

Published: June 24, 2024

In this work, a design strategy for deep-blue multiresonance thermally activated delayed fluorescence (MR-TADF) molecules was developed by the fusion of weak O–B–N MR units and peripheral modification strong electron-donating diphenylamino group, resulting in hybrid long- short-range charge transfer excitation characteristics with accelerated properties. As proof-of-concept molecule, DOBN shows narrowband emission peaking at 438 nm small full width half-maximum (fwhm) 19 as well high efficiency 51%. Finally, external quantum efficiencies (EQEs) CIEy chromaticity coordinates were realized both solution-processed (27.7%, 0.03) vacuum-evaporated (35.4%, 0.04) hyperfluorescence organic light-emitting diodes (OLEDs) employing emitter. These results demonstrate feasible molecular high-performance MR-TADF emitters represent state-of-the-art performances OLEDs terms EQEs color coordinates.

Language: Английский

Organoboron-based multiple-resonance emitters: synthesis, structure–property correlations, and prospects DOI Creative Commons
Masashi Mamada, Masahiro Hayakawa, Junki Ochi

et al.

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

Citations

124
Synergetic Modulation of Steric Hindrance and Excited State for Anti‐Quenching and Fast Spin‐Flip Multi‐Resonance Thermally Activated Delayed Fluorophore DOI

Jia‐Ming Jin,

Denghui Liu,

Wen‐Cheng Chen

et al.

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

Citations

39
Acceleration of reverse intersystem crossing in multi-resonance TADF emitter DOI
Yang Zou, Mingxin Yu,

Yulin Xu

et al.

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

Published: Feb. 15, 2024

Language: Английский

Citations

35
Highly efficient pure-blue organic light-emitting diodes based on rationally designed heterocyclic phenophosphazinine-containing emitters DOI Creative Commons

Longjiang Xing,

Jianghui Wang, Wen‐Cheng Chen

et al.

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

Citations

30
B‒N covalent bond-involved π-extension of multiple resonance emitters enables high-performance narrowband electroluminescence DOI Creative Commons
Xingyu Huang, Jiahui Liu,

Yulin Xu

et al.

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

Citations

24
“Core–Shell” Wave Function Modulation in Organic Narrowband Emitters DOI
Masahiro Hayakawa, Xun Tang, Yuta Ueda

et al.

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

Citations

20
Excited‐State Engineering Enables Efficient Deep‐Blue Light‐Emitting Diodes Exhibiting BT.2020 Color Gamut DOI

Rui‐Zhi An,

Yuqi Sun,

Hao‐Yang Chen

et al.

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

Citations

19
Purely organic room-temperature phosphorescence sensitizers for highly efficient hyperfluorescence OLEDs DOI Creative Commons
Jiajie Zeng,

Shaoxin Song,

Yan Fu

et al.

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

Citations

4
Regulation of Multiple Resonance Delayed Fluorescence via Through‐Space Charge Transfer Excited State towards High‐Efficiency and Stable Narrowband Electroluminescence DOI
Sai Luo, Junjie Wang, Nengquan Li

et al.

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

Citations

39
Recent progress in multi-resonance thermally activated delayed fluorescence emitters with an efficient reverse intersystem crossing process DOI

Xu‐Feng Luo,

Xunwen Xiao, You‐Xuan Zheng

et al.

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

Citations

33