RGB Thermally Activated Delayed Fluorescence Emitters for Organic Light‐Emitting Diodes toward Realizing the BT.2020 Standard

Advanced Science, Journal Year: 2023, Volume and Issue: 10(28)

Published: Aug. 16, 2023

Abstract With the surging demand for ultra‐high‐resolution displays, International Telecommunication Union (ITU) announce next‐generation color gamut standard, named ITU‐R Recommendation BT.2020, which not only sets a seductive but challenging milestone display technologies also urges researchers to recognize importance of coordinates. Organic light‐emitting diodes (OLEDs) are an important technology in current daily life, they face challenges approaching BT.2020 standard. Thermally activated delayed fluorescence (TADF) emitters have bright prospects OLEDs because possess 100% theoretical exciton utilization. Thus, development TADF emitting primary red (R), green and blue (B) emission is great significance. Here, comprehensive overview latest advancements that exhibit Commission Internationale de l'Éclairage (CIE) coordinates surpassing National Television System Committee (NTSC) standards presented. Rational strategies molecular designs, as well resulting photophysical properties OLED performances, discussed elucidate underlying mechanisms shifting CIE both donor‐acceptor multiple resonance (MR) typed toward Finally, realization wide‐color‐gamut standard this research area provided.

Language: Английский

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Deep-blue organic light-emitting diodes for ultrahigh-definition displays

Nature Photonics, Journal Year: 2024, Volume and Issue: 18(11), P. 1161 - 1169

Published: Aug. 19, 2024

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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“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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Stepwise Toward Pure Blue Organic Light‐Emitting Diodes by Synergetically Locking and Shielding Carbonyl/Nitrogen‐Based MR‐TADF Emitters

Advanced Science, Journal Year: 2024, Volume and Issue: 11(28)

Published: May 5, 2024

Deep-blue multi-resonance (MR) emitters with stable and narrow full-width-at-half-maximum (FWHM) are of great importance for widening the color gamut organic light-emitting diodes (OLEDs). However, most planar MR vulnerable to intermolecular interactions from both host guest, causing spectral broadening exciton quenching in thin films. Their emission solid state is environmentally sensitive, purity often inferior that solutions. Herein, a molecular design strategy presented simultaneously narrows FWHM suppresses by combining intramolecular locking peripheral shielding within carbonyl/nitrogen-based core. Intramolecularly bears narrower 2,10-dimethyl-12,12-diphenyl-4H-benzo[9,1]quinolizino[3,4,5,6,7-defg]acridine-4,8(12H)-dione solution further peripheral-shielding groups, deep-blue emitter (12,12-diphenyl-2,10-bis(9-phenyl-9H-fluoren-9-yl)-4H-benzo[9,1]quinolizino[3,4,5,6,7-defg]acridine-4,8(12H)-dione, DPQAO-F) exhibits ultra-pure (c.a., 24 nm) minimal variations (∆FWHM ≤ 3 films over wide doping range. An OLED based on DPQAO-F presents maximum external quantum efficiency (EQE

Language: Английский

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Narrow Band Organic Emitter for Pure Green Solution‐Processed Electroluminescent Devices with CIE Coordinate y of 0.77

Advanced Optical Materials, Journal Year: 2024, Volume and Issue: 12(21)

Published: April 9, 2024

Abstract While the development of solution‐processed organic light‐emitting diodes (sOLEDs) utilizing multiple resonance‐induced thermally activated delayed fluorescence (MR‐TADF) is highly significant, it restricted by limited solubility and film‐forming property resulting from rigid conjugate planarity MR‐TADF materials. Herein, an effective strategy presented to obtain narrowband emitters introducing inert steric bulky hindrance group into resonance skeleton, thereby mitigating issues arising intermolecular packing‐induced poor solution processing ability quenching effects. The target emitter, designed as 3CzSF‐BN, exhibits pure‐green emission with a peak at 520 nm small full width half maximum (FWHM) 30 (0.14) eV. Remarkably, achieves exceptional photoluminescence quantum yield (PLQY) 100% notable advancements in attributes. optimized bottom‐emitting sOLED (BE‐sOLED) device external efficiency (EQE) over 20% Commission Internationale de I’Éclairage (CIE) coordinates (0.214, 0.716). Notably, top‐emitting (TE‐sOLED) ultra‐pure green color FWHM 22 CIE (0.138, 0.771), highlighting effectiveness this designing high‐performance

Language: Английский

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Realizing highly efficient deep-blue organic light-emitting diodes towards Rec.2020 chromaticity by restricting the vibration of the molecular framework

Chemical Science, Journal Year: 2024, Volume and Issue: 15(13), P. 4790 - 4796

Published: Jan. 1, 2024

A deep blue TADF emitter composed of rigid D and units was developed. BOC-PSi-based OLED exhibited not only an impressive EQE max approaching 20%, but also a superior color purity the Rec.2020 standard.

Language: Английский

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Acceptor Copolymerized Axially Chiral Conjugated Polymers with TADF Properties for Efficient Circularly Polarized Electroluminescence

Advanced Science, Journal Year: 2024, Volume and Issue: 11(23)

Published: March 29, 2024

Abstract Chiral conjugated polymer has promoted the development of efficient circularly polarized electroluminescence (CPEL) device, nevertheless, it remains a challenge to develop chiral polymers with high performance. Herein, by acceptor copolymerization axially biphenyl emitting skeleton and benzophenone, pair namely R ‐ PAC S are synthesized. The target exhibit obvious thermally activated delayed fluorescence (TADF) activities photoluminescence quantum yields 81%. Moreover, display significant luminescence features, dissymmetry factor (| g lum |) nearly 3 × 10 −3 . By using as emitters, corresponding organic light‐emitting diodes (CP‐OLEDs) CPEL signals | EL 3.4 maximum external efficiency (EQE max ) 17.8%. Notably, considering both EQE comprehensively, device performance is best among all reported CP‐OLEDs emitters. This work provides facile approach constructing TADF discloses potential luminescent skeletons in architecting high‐performance CP‐OLEDs.

Language: Английский

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The degradation mechanism of multi-resonance thermally activated delayed fluorescence materials

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

Published: Jan. 4, 2025

1,4-Azaborine-based arenes are promising electroluminescent emitters with thermally activated delayed fluorescence (TADF), offering narrow emission spectra and high quantum yields due to a multi-resonance (MR) effect. However, their practical application is constrained by limited operational stability. This study investigates the degradation mechanism of MR-TADF molecules. Electroluminescent devices incorporating these compounds display varied lifetimes, uncorrelated excitonic stability or external efficiency roll-off. Bulk electrolysis reveals significant instability in radical cationic forms compounds, device lifetime linked Faradaic yield oxidation. Comprehensive chemical analyses corroborate that byproducts originated from intramolecular cyclization cation, followed hydrogen atom transfer. The further supported enhanced observed deuterated emitter, attributed secondary kinetic isotope These findings provide insights into stabilizing effects deuteration mechanism-driven strategies for designing improved longevity. often constrains application. Here, authors report direct correlation between oxidative emitter

Language: Английский

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