Exceeding 30 % External Quantum Efficiency in Non‐doped OLEDs Utilizing Solution Processable TADF Emitters with High Horizontal Dipole Orientation via Anchoring Strategy

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(45)

Published: Sept. 21, 2022

Strategies to enhance the ratio of molecular horizontal emitting dipole orientation (Θ∥ ) for thermally activated delayed fluorescence (TADF) emitters have unlocked full potential efficiencies evaporated devices, which, however, remain elusive solution-processed ones. Here, a strategic design solution processable TADF featuring high Θ∥ s is proposed by attaching flexible chains ended with bipolar 9,9'-spirobi[fluorene] subunits as anchoring groups onto core. It's unveiled that not only via enlarging planarity, but also benefit photoluminescence in pristine films. The corresponding non-doped OLEDs substantiate an unprecedented maximum external quantum efficiency (EQEmax )>30 %. Meanwhile, combining these compounds sensitizers, and multiple resonance final emitter, achieve EQEmax 25.6 % narrow width at half 29 nm.

Language: Английский

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All-fluorescence white organic light-emitting diodes with record-beating power efficiencies over 130 lm W‒1 and small roll-offs

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Sept. 2, 2022

Improving power efficiency (PE) and reducing roll-off are of significant importance for the commercialization white organic light-emitting diodes (WOLEDs) in consideration energy conservation. Herein, record-beating PE 130.7 lm W-1 outstanding external quantum (EQE) 31.1% achieved all-fluorescence two-color WOLEDs based on a simple sandwich configuration emitting layer consisting sky-blue orange delayed fluorescence materials. By introducing red dopant, three-color with high color rendering index constructed an interlayer sensitization configuration, furnishing ultrahigh 110.7 EQE 30.8%. More importantly, both maintain excellent PEs at operating luminance smaller roll-offs than reported state-of-the-art WOLEDs, further device optimization realizes comprehensive performances low driving voltages, large luminance, long operational lifetimes. The underlying mechanisms impressive elucidated by host-tuning effect electron-trapping effect, providing useful guidance development energy-conserving WOLEDs.

Language: Английский

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Molecular Engineering Enables TADF Emitters Well Suitable for Non‐Doped OLEDs with External Quantum Efficiency of Nearly 30%

Advanced Functional Materials, Journal Year: 2022, Volume and Issue: 32(19)

Published: Feb. 4, 2022

Abstract Non‐doped organic light‐emitting diodes (OLEDs) are particularly appealing due to the merit of extremely simple device structure. However, performance non‐doped OLEDs is usually far inferior than that doped devices, mainly lack desirable emitters. An ideal emitter for should not merely be highly emissive in host matrix but also capable delivering excellent properties its condensed state. Herein, through molecular engineering, an “axial and equatorial carbazolyl extension” approach manipulate packing behavior developed, thus, awarded with superior neat film. Based on this approach, simply modifying conventional acridine donor a thermally activated delayed fluorescence (TADF) carbazole moieties way hyper‐conjugation, two new TADF emitters skeleton being extended both horizontally vertically by constructed. The resulted reveal superb simultaneous thermal morphological stabilities, photophysical behaviors, charge transporting ability their Owing merits these synergistic properties, efficient green OLED state‐of‐the‐art external quantum efficiency nearly 30% realized.

Language: Английский

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Through-Space Conjugated Molecule with Dual Delayed Fluorescence and Room-Temperature Phosphorescence for High-Performance OLEDs

ACS Materials Letters, Journal Year: 2023, Volume and Issue: 5(3), P. 664 - 672

Published: Jan. 30, 2023

Purely organic materials with room-temperature phosphorescence usually have much longer triplet state lifetimes than noble-metal containing phosphorescent materials, which lead to severe exciton quenching and inferior electroluminescence (EL) performance when applied in light-emitting diodes (OLEDs). Herein, a novel through-space conjugated molecule (2,3-PICz-XT) dual delayed fluorescence is developed. Owing suitable energy levels strong spin–orbit coupling among excited states, 2,3-PICz-XT has short at microsecond scale high photoluminescence quantum yields neat doped films. can function as efficient emitters OLEDs, providing external efficiencies (ηexts) of up 32.73% small efficiency roll-offs. It also efficiently sensitize various thermally activated (TADF) yield excellent EL performances. Impressively, the hyperfluorescence OLEDs using sensitizer for multiple resonance TADF attain narrow spectra greatly improved ηexts over 35%. To best our knowledge, most emitter ever reported materials.

Language: Английский

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High‐efficiency thermally activated delayed fluorescence materials via a shamrock‐shaped design strategy to enable OLEDs with external quantum efficiency over 38%

Aggregate, Journal Year: 2023, Volume and Issue: 4(6)

Published: July 6, 2023

Abstract To achieve highly‐efficient organic light‐emitting diodes (OLEDs), great efforts have been devoted into constructing thermally activated delayed fluorescence (TADF) with high horizontal dipole ratios (Θ // ). Here, we proposed a design strategy by integrating rigid electron‐accepting oxygen‐bridged boron core triple electron‐donating groups, which exhibited “shamrock‐shape”, namely BO‐3DMAC and BO‐3DPAC. Benefiting from the large‐planar skeletons brought shamrock‐shaped design, BO‐3DPAC exhibit Θ of 84%/70% 93%/94% in neat/doped films, respectively, finally furnish excellent external quantum efficiencies (EQEs) up to 28.3% 38.7% 20 wt% doped OLEDs sky‐blue emission, as well adequate EQEs 21.0% 16.7% nondoped OLEDs. This work unveils promising establish high‐Θ TADF emitters molecular structures using design.

Language: Английский

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Regulating the proximity effect of heterocycle-containing AIEgens

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: June 24, 2023

Abstract Proximity effect, which refers to the low-lying ( n ,π*) and (π,π*) states with close energy levels, usually plays a negative role in luminescent behaviors of heterocyclic luminogens. However, no systematic study attempts reveal manipulate proximity effect on properties. Here, we report series methylquinoxaline derivatives different electron-donating groups, show photophysical properties aggregation-induced emission behaviors. Experimental results theoretical calculation gradually changed levels coupling effects closely related states, intrinsically regulate these With intrinsic nature heterocycle-containing compounds, they are utilized for sensors information encryption dynamic responses acid/base stimuli. This work reveals both positive impacts systems provides perspective develop functional responsive luminogens

Language: Английский

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Doublet-emissive materials for organic light-emitting diodes: exciton formation and emission processes

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 52(9), P. 2875 - 2885

Published: Jan. 1, 2023

This tutorial review introduces the emission mechanism, recent research, advantages, challenge and future outlook of novel emissive materials with doublet state their application in OLEDs.

Language: Английский

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Durable organic nonlinear optical membranes for thermotolerant lightings and in vivo bioimaging

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: July 22, 2023

Abstract Organic nonlinear optical materials have potential in applications such as lightings and bioimaging, but tend to low photoluminescent quantum yields are prone lose the activity. Herein, we demonstrate weave large-area, flexible organic membranes composed of 4-N,N-dimethylamino-4ʹ-Nʹ-methyl-stilbazolium tosylate@cyclodextrin host-guest supramolecular complex. These exhibited a record high photoluminescence yield 73.5%, could continuously emit orange luminescence even being heated at 300 °C, thus enabling fabrication thermotolerant light-emitting diodes. The property these can be well-preserved polar environment. assemblies with multiphoton absorption characteristics were used for vivo real-time imaging Escherichia coli 1000 nm excitation. findings achieve scalable yields, good stability against thermal stress environment high-performance, durable optoelectronic devices humanized bio-probes.

Language: Английский

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Efficient deep-blue luminescence based on dual-channel intra/intermolecular exciplexes

Science Advances, Journal Year: 2023, Volume and Issue: 9(20)

Published: May 19, 2023

Highly efficient and stable blue organic light-emitting diodes (OLEDs) cannot be easily obtained simultaneously. In particular, the efficiency roll-off as a reference index to evaluate lifetime of deep-blue OLED at high luminescence is still severe. A novel molecule (CzSiTrz) connected with carbazole triazine fragments by nonconjugated silicon atom designed. An intramolecular charge transfer emission intermolecular exciplex in aggregated state are obtained, resulting dual-channel intra/intermolecular (DCIE) fast reverse intersystem crossing (RISC). Deep-blue Commission Internationale de l'Eclairage (CIE) coordinates (0.157, 0.076) record-high external quantum (EQE) 20.35% luminance (5000 cd m-2) accomplished. Simple molecular synthesis device fabrication this strategy give unique approach realizing high-performance electroluminescence.

Language: Английский

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Secondary donor-acceptor group enable efficient pure green organic light-emitting devices based on multi-resonance TADF emitters

Chemical Engineering Journal, Journal Year: 2024, Volume and Issue: 481, P. 148794 - 148794

Published: Jan. 14, 2024

Language: Английский

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