Highly efficient multi-resonance thermally activated delayed fluorescence material toward a BT.2020 deep-blue emitter

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

Published: April 2, 2024

Abstract An ultrapure deep-blue multi-resonance-induced thermally activated delayed fluorescence material (DOB2-DABNA-A) is designed and synthesized. Benefiting from a fully resonating extended helical π-conjugated system, this compound has small ΔE ST value of 3.6 meV sufficient spin–orbit coupling to exhibit high-rate constant for reverse intersystem crossing ( k RISC = 1.1 × 10 6 s –1 ). Furthermore, an organic light-emitting diode employing DOB2-DABNA-A as emitter fabricated; it exhibits emission at 452 nm with full width half maximum 24 nm, corresponding Commission Internationale de l’Éclairage (CIE) coordinates (0.145, 0.049). The high reduces the efficiency roll-off, resulting in external quantum (EQE) 21.6% 1000 cd m –2 .

Language: Английский

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Efficient Deep‐Blue Multiple‐Resonance Emitters Based on Azepine‐Decorated ν‐DABNA for CIE_y below 0.06

Advanced Materials, Journal Year: 2024, Volume and Issue: 36(30)

Published: May 2, 2024

Abstract Ultrapure deep‐blue emitters are in high demand for organic light‐emitting diodes (OLEDs). Although color coordinates serve as straightforward parameters assessing purity, precise control over the maximum wavelength and full‐width at half‐maximum is necessary to optimize OLED performance, including luminance efficiency luminous efficacy. Multiple‐resonance (MR) promising candidates achieving ideal luminescence properties; consequently, a wide variety of MR frameworks have been developed. However, most these experience displacement from color, which limits their practical applicability. Therefore, molecular design that compatible with modulating energy levels output particularly valuable. Here, it demonstrated azepine donor unit induces an appropriate blue‐shift emission while maintaining efficient characteristics, photoluminescence quantum yield, narrow emission, fast reverse intersystem crossing rate. OLEDs using newly developed based on ν ‐DABNA framework simultaneously exhibit ≈30%, efficacy ≈20 lm W −1 , exceptional purity Commission Internationale de l’Éclairage low (0.14, 0.06), notably operational stability. These results demonstrate unprecedentedly compared those observed previously reported emitters.

Language: Английский

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Bright, efficient, and stable pure-green hyperfluorescent organic light-emitting diodes by judicious molecular design

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

Published: April 12, 2024

Abstract To fulfill ultra-high-definition display, efficient and bright green organic light-emitting diodes with Commission Internationale de l’Éclairage y-coordinate ≥ 0.7 are required. Although there some preceding reports of highly devices based on pure-green multi-resonance emitters, the efficiency rolloff device stabilities for those still unsatisfactory. Herein, we report rational design two emitters achieving stable CIE x,y s that close to NTSC BT. 2020 standards. In this study, our thermally activated delayed fluorescence OLEDs result in y up 0.74. hyperfluorescent architecture, x further meet x-coordinate requirements, i.e., (0.21) (0.17), while keeping their ~ 0.7. Most importantly, display high maximum external quantum efficiencies over 25% luminance 10 5 cd m −2 suppressed rolloffs (external ~20% at 4 ) long LT 95 600 h.

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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Sulfur-locked multiple resonance emitters for high performance orange-red/deep-red OLEDs

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Jan. 2, 2025

Language: Английский

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Recent progress, challenges, and opportunities in 2D materials for flexible displays

Nano Today, Journal Year: 2024, Volume and Issue: 56, P. 102256 - 102256

Published: April 6, 2024

Language: Английский

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Chiral Co‐Assembly with Narrowband Multi‐Resonance Characteristics for High‐Performance Circularly Polarized Organic Light‐Emitting Diodes

Advanced Materials, Journal Year: 2024, Volume and Issue: 36(38)

Published: July 25, 2024

A promising kind of ternary chiral co-assemblies with high PLQY, large dissymmetry factor (g

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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Tailoring Ultra‐Narrowband Tetraborylated Multiple Resonance Emitter for High‐Performance Blue OLED

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

Published: Oct. 10, 2024

Ultra-narrowband multiple resonance (MR) emitters are a key component in the fabrication of highly efficient and stable blue organic light-emitting diodes (OLEDs). To explore theoretical boundaries wavelength full width at half maximum (FWHM) emitters, currently narrowest boron-based MR emitter is carefully designed by integrating superior v-DABNA BBCz-DB structures under auspices ingenious short-range charge-transfer region regulation strategy. The target tetraboron compound TB-PB demonstrates emission with an 473 nm, small FWHM 12 nm CIEy coordinate 0.14. Benefiting from emitter's high photoluminescence quantum yield (99%), low excited-state energy (2.74 eV) short delayed fluorescence lifetime (0.53 µs), corresponding OLED achieves exceptional efficiencies 36.4%, 49.1 cd A

Language: Английский

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Peripheral Substitution Engineering of MR‐TADF Emitters Embedded With B‒N Covalent Bond Towards Efficient BT.2020 Blue Electroluminescence

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

Published: Oct. 15, 2024

Compared with the classical boron/nitrogen (B/N) doped ones, multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters embedded B-N covalent bond behave a significantly blue-shifted narrowband TADF, and thus show greater potential in ultrapure blue organic light-emitting diodes (OLEDs). As proof of concept, herein peripheral substitution engineering is demonstrated based on such B‒N parent core. The simple approach found to ensure easy synthesis via one-pot lithium-free borylation-annulation, manipulate excited states through different electronic coupling between core substituent, introduce steric hindrance minimize unwanted spectral broadening. Impressively, OLEDs are realized give high external quantum efficiency 20.3% together Commission Internationale de l'Éclairage coordinates (0.152, 0.046). performance well competent those B/N MR-TADF emitters, clearly highlighting that framework novel promising paradigm towards efficient BT.2020 standard.

Language: Английский

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