Synergistic Modulation of Excited State Ingredients and Chiroptical Activity for High‐Performance Pure‐Green Circularly Polarized Electroluminescence DOI
Haoxin Huang, Nengquan Li, Wendi Li

et al.

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: unknown

Published: May 14, 2024

Abstract The integration of chiral elements within a multiple resonance (MR) motif affords prospective avenue to construct satisfying emitters tailored for state‐of‐the‐art circularly polarized organic light–emitting diodes (CP‐OLEDs). However, the concurrently realizing both high luminescence efficiency and favorable dissymmetry factors ( g PL ) still remains formidable challenge, particularly when aligning with requirement color purity. Herein, dual‐pronged approach is proposed reconcile such trade‐offs by directly fusing secondary donor onto MR scaffold, thereby facilitating hybrid short/long‐range charge‐transfer fine‐tuned compositions. Theoretical calculations unveil pronounced impact on meticulously refining characteristics excited states, therefore yielding considerable 3.3 × 10 −3 , along fluorescence quantum yield 0.97, rapid reverse intersystem crossing rate 3.06 5 s −1 in one embodiment. Leveraging these merits, electroluminescence devices incorporating them as dopants exhibit exceptional performance, showcasing peak external 36.6% remarkable Commission Internationale de L'Eclairage coordinates (0.19, 0.71), which represent most notable achievements among pure‐green CP‐OLEDs.

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

117
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

32
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

30
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

26
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

19
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

37
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

29
“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

16
Recent Progress of Thermally Activated Delayed Fluorescent Materials with Narrowband Red, Green, and Blue (RGB) Emission DOI
Ping Li, Wenjing Li, Yewen Zhang

et al.

ACS Materials Letters, Journal Year: 2024, Volume and Issue: 6(5), P. 1746 - 1768

Published: April 2, 2024

Narrowband thermally activated delayed fluorescence (TADF) materials have received widespread attention due to their promising applications in organic light-emitting diodes with high-definition displays. Great efforts been done achieve full-color narrowband emissions donor–acceptor (D–A) and multiple-resonance (MR) TADF materials. In comparison the D–A materials, MR-based basically showed smaller full width at half-maximum (fwhm) of spectra owing inherent structural vibration inhibition electronic transition characteristics. Herein, review summarizes current research progress on both MR blue, green red emission regions fwhm less than 70 nm concentrating molecular design strategies, photophysical properties corresponding device performance, proposes some possible future topic. This aims give physical insight structure–property relationship such offer guidance for further developing provide a structured database platform high-throughput or machine learning research.

Language: Английский

Citations

15
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

15