Modulating electronic confinement and structural distortion of multiple resonance emitters enables high-performance ultrapure blue OLED

Chemical Engineering Journal, Год журнала: 2024, Номер 482, С. 148876 - 148876

Опубликована: Янв. 17, 2024

Язык: 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, Год журнала: 2024, Номер unknown

Опубликована: Окт. 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.

Язык: Английский

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Deep‐Blue OLEDs with BT. 2020 Blue Gamut, External Quantum Efficiency Approaching 40%

Advanced Materials, Год журнала: 2025, Номер unknown

Опубликована: Фев. 11, 2025

Abstract The hyperfluorescence (HF) technology holds great promise for the development of high‐quality organic light‐emitting diodes (OLEDs) their excellent color purity, high efficiency, and low‐efficiency roll‐off. Sensitizer plays a crucial role in performance HF devices. However, designing sensitizers with simultaneous photoluminescence quantum yield (PLQY), rapid radiative decay ( k r ), fast reverse intersystem crossing rate RISC ) poses challenge, particularly thermally activated delayed fluorescence (TADF) targeting deep‐blue device. Herein, by introducing boron‐containing multi‐resonance‐type acceptor into multi‐ tert ‐butyl‐carbazole encapsulated benzene molecular skeleton, two TADF emitters featuring hybridized multi‐channel charge‐transfer pathways, including short‐range multi‐resonance, weakened through‐bond, compact face‐to‐face through‐space charge‐transfer. Benefiting from rational design, proof‐of‐concept exhibit 5.3 × 10 7 s −1 , up to 5.9 5 PQLY near‐unity, as well ideal emission both solution film. Consequently, corresponding devices not only achieve chromaticity coordinates that fully comply latest BT. 2020 standards, but also showcase record‐high maximum external efficiencies nearing 40%, along suppressed efficiency

Язык: Английский

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Phenoxazine and phenothiazine embedded Multi-Resonance emitters for highly efficient Pure-Red OLEDs with improved color purity

Chemical Engineering Journal, Год журнала: 2023, Номер 471, С. 144565 - 144565

Опубликована: Июль 3, 2023

Язык: Английский

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Rational Multidimensional Shielded Multiple Resonance Emitter Suppresses Concentration Quenching and Spectral Broadening for Solution-Processed Organic Light-Emitting Diodes

ACS Applied Materials & Interfaces, Год журнала: 2023, Номер 15(33), С. 39669 - 39676

Опубликована: Авг. 14, 2023

Thermally activated delayed fluorescence (TADF) emitters based on multiple resonance (MR) effects are promising for high-definition organic light-emitting diodes (OLEDs) with narrowband emission and high efficiency. However, they still face the challenges of aggregation-caused quenching (ACQ) spectral broadening. Solution-processable MR-TADF an external quantum efficiency (EQE) >20% a full width at half-maximum (fwhm) <30 nm have rarely been reported. To construct ACQ-resistant without sacrificing color purity, aggregation-induced material 6TBN rigid B,N-containing polycyclic aromatic hydrocarbon core four carbazole substituents as well 12 tert-butyl groups periphery is designed. The multidimensional shielded effect largely limits ACQ, intermolecular interactions, Consequently, solution-processed OLEDs exhibit maximum EQE 23.0% purity fwhm 25 nm. Furthermore, nondoped device achieves (12.3%) merely slight widening to 27 This work provides feasible strategy achieve materials resistance concentration purity.

Язык: Английский

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Highly Horizontal Oriented Tricomponent Exciplex Host with Multiple Reverse Intersystem Crossing Channels for High‐Performance Narrowband Electroluminescence and Eye‐Protection White Organic Light‐Emitting Diodes

Advanced Materials, Год журнала: 2024, Номер 36(33)

Опубликована: Июнь 19, 2024

Despite multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters with small full-width at half maximum are attractive for wide color-gamut display and eye-protection lighting applications, their inefficient reverse intersystem crossing (RISC) process long exciton lifetime induce serious efficiency roll-off, which significantly limits development. Herein, a novel device concept of building highly efficient tricomponent exciplex multiple RISC channels is proposed to realize reduced quenching enhanced upconversion nonradiative triplet excitons, subsequently used as host high-performance MR-TADF organic light-emitting diodes (OLEDs). Compared traditional binary exciplex, the exhibits obviously improved photoluminescence quantum yield, emitting dipole orientation rate constant, record-breaking external (EQE) 30.4% achieved p-PhBCzPh: PO-T2T: DspiroAc-TRZ (50: 20: 30) based OLED. Remarkably, EQEs 36.2% 40.3% ultralow roll-off 26.1% 30.0% 1000 cd m

Язык: Английский

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Synergistic Enhancement of Emitting Dipole Orientation between Pt‐Based Phosphorescent Sensitizers and Boron‐Based Multi‐Resonance Fluorescent Emitters for High‐Performance Phosphor‐Sensitized Fluorescent Organic Light‐Emitting Diodes

Small Structures, Год журнала: 2024, Номер 5(6)

Опубликована: Фев. 16, 2024

Phosphor‐sensitized fluorescent (PSF) organic light‐emitting diodes (OLEDs) emerge as an attractive solution for realizing high‐performance displays with high color purity, meeting the Broadcast Television 2020 (BT.2020) requirements, by fully harnessing benefits of both phosphorescent and emitters. Herein, synergistic effect a Pt sensitizer boron (B)‐based multi‐resonance (MR)‐fluorescent emitter are introduced to enhance efficiency blue‐emitting PSF–OLEDs. Notably, it is confirmed that interaction between empty pz orbital in atom MR unpaired electrons dz 2 plays crucial role. The combination results enhancement horizontal emitting dipole orientation (EDO) 81%, marked improvement compared individual components phosphor (69%) or (78%). approach leads realization PSF‐OLEDs maximum external quantum 25%, peak intensity at 465 nm electroluminescence spectrum, full width half 29 nm, achieved enhancing outcoupling. In these findings, insight provided into design strategies developing PSF systems based on B‐terminal achieve efficient energy transfer well improved EDO.

Язык: Английский

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Host Engineering of Deep‐Blue‐Fluorescent Organic Light‐Emitting Diodes with High Operational Stability and Narrowband Emission

Advanced Science, Год журнала: 2024, Номер unknown

Опубликована: Сен. 20, 2024

Abstract The realization of highly operationally stable blue organic light‐emitting diodes (OLEDs) is a challenge in both academia and industry. This paper describes the development anthracene–dibenzofuran host materials, 2‐(10‐(naphthalen‐1‐yl)anthracen‐9‐yl)naphtho[2,3‐b]benzofuran ( Host 1 ) 2‐(10‐([1,1′‐biphenyl]‐2‐yl)anthracen‐9‐yl)naphtho[2,3‐b]benzofuran 2 ), namely for use emissive layer an OLED stack. A multiple‐resonance thermally activated delayed serves as fluorescence emitter exhibits initial luminance 1000 cd m −2 long operational stability (i.e., time to decay 90% luminance) 249 h. Furthermore, deep‐blue with optimized top‐emitting architecture high current efficiency 154.3 −1 , fabricated calibrated Commission International de l’Éclairage y chromaticity coordinate 0.048. Moreover, emission spectrum this has narrowband peak at 476 nm full width half maximum (FWHM) 16 nm. work provides valuable insights into design anthracene‐based materials highlights importance optimization improving OLEDs.

Язык: Английский

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Four‐Membered Ring‐Embedded Cycloarene Enabling Anti‐Aromaticity and Ultra‐Narrowband Emission

Angewandte Chemie International Edition, Год журнала: 2024, Номер unknown

Опубликована: Июль 11, 2024

Abstract The synthesis of fully fused π‐conjugated cycloarenes embedded with nonbenzenoid aromatics is challenging. In this work, the first example four‐membered ring‐embedded cycloarene ( MF2 ) was designed and synthesized in single‐crystal form by macrocyclization ring fusion strategies. For comparison, single bond‐linked chiral macrocycle MS2 without two rings its linear‐shaped polycyclic benzenoid monomer L1 were also synthesized. pronounced anti‐aromaticity significantly adjusts electronic structures photophysical properties cycloarene, resulting an enhancement photoluminescence quantum yield (PLQY) from 10.66 % 10.74 for , respectively, to 54.05 which highest PLQY among reported cycloarenes. Notably, owing anti‐aromatic that reduce structural displacements, exhibits ultra‐narrowband emission a single‐digit full‐width at half‐maximum (FWHM) only 7 nm (0.038 eV), sets new record all organic narrowband luminescent molecules, represents conventional aromatic hydrocarbons (PAHs) devoid heteroatoms.

Язык: Английский

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Spiro‐Carbon‐Locking and Sulfur‐Embedding Strategy for Constructing Deep‐Red Organic Electroluminescent Emitter with High Efficiency

Angewandte Chemie International Edition, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 4, 2024

Abstract The discovery of multiple resonance thermally activated delayed fluorescence (MR‐TADF) materials with remarkable narrowband emission has opened a new avenue for the development organic light‐emitting diodes (OLEDs) high color purity. However, lack construction strategies purely red MR‐TADF significantly impedes their application in full‐color high‐definition displays. Herein, we propose unique and handy approach spiro‐carbon‐locking sulfur‐embedding strategy to modify parent framework, resulting emitter reported molecule (namely, FSBN) demonstrates pure an maximum 621 nm toluene solution. OLED FSBN as exhibits Commission Internationale de l’Éclairage (CIE) coordinates (0.67, 0.33), which exactly matches standard defined by National Television Standards Committee (NTSC). Importantly, single‐host achieves power efficiency (PE) up 50.1 lm W −1 , suggesting potential low consumption OLEDs.

Язык: Английский

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