B‐N Covalent Bond Embedded Double Hetero‐[n]helicenes for Pure Red Narrowband Circularly Polarized Electroluminescence with High Efficiency and Stability

Advanced Materials, Journal Year: 2023, Volume and Issue: 36(5)

Published: Sept. 12, 2023

Chiral B/N embedded multi-resonance (MR) emitters open a new paradigm of circularly polarized (CP) organic light-emitting diodes (OLEDs) owing to their unique narrowband spectra. However, pure-red CP-MR and devices remain exclusive in literature. Herein, by introducing B-N covalent bond lower the electron-withdrawing ability para-positioned B-π-B motif, first pair double hetero-[n]helicenes (n = 6 7) emitter peaking 617 nm with small full-width at half-maximum 38 high photoluminescence quantum yield ≈100% toluene is developed. The intense mirror-image CP light produced enantiomers characterized dissymmetry factors (g

Language: Английский

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Boron-containing helicenes as new generation of chiral materials: opportunities and challenges of leaving the flatland

Chemical Science, Journal Year: 2024, Volume and Issue: 15(20), P. 7408 - 7440

Published: Jan. 1, 2024

Recent advances in synthesis have opened the way to a variety of boron helicenes. We highlight main achievements these chiral compounds and discuss their photophysical properties potential as functional materials.

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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Introducing Spiro‐locks into the Nitrogen/Carbonyl System towards Efficient Narrowband Deep‐blue Multi‐resonance TADF Emitters

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(40)

Published: Aug. 19, 2023

The current availability of multi-resonance thermally activated delayed fluorescence (MR-TADF) materials with excellent color purity and high device efficiency in the deep-blue region is appealing. To address this issue emerged nitrogen/carbonyl MR-TADF system, we propose a spiro-lock strategy. By incorporating spiro functionalization into concise molecular skeleton, series emitters (SFQ, SOQ, SSQ, SSeQ) can enhance rigidity, blue-shift emission peak, narrow band, increase photoluminescence quantum yield by over 92 %, suppress intermolecular interactions film state. referent CZQ without structure has more planar its bluer solution state redshifts 40 nm serious spectrum broadening low PLQY As result, SSQ achieves an external 25.5 % peak at 456 small full width half maximum 31 simple unsensitized device, significantly outperforming CZQ. This work discloses importance spiro-junction modulating emitters.

Language: Английский

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Tailored Design of π‐Extended Multi‐Resonance Organoboron using Indolo[3,2‐b]Indole as a Multi‐Nitrogen Bridge

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(48)

Published: Oct. 9, 2023

Extending the π-skeletons of multi-resonance (MR) organoboron emitters can feasibly modulate their optoelectronic properties. Here, we first adopt indolo[3,2-b]indole (32bID) segment as a multi-nitrogen bridge and develop high-efficiency π-extended narrowband green emitter. This moiety establishes not only high-yield one-shot multiple Bora-Friedel-Crafts reaction towards MR skeleton, but compact N-ethylene-N motif for red-shifted emission. An emission peak at 524 nm, small full width half maximum 25 nm high photoluminescence quantum yield 96 % are concurrently obtained in dilute toluene. The extended molecular plane also results large horizontal emitting dipole orientation ratio 87 %. A external efficiency (EQE) 36.6 power 135.2 lm/W thereafter recorded corresponding device, allowing low roll-off with EQEs 34.5 28.1 luminance 1,000 cd/m2 10,000 , respectively.

Language: Английский

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Marching Toward Long‐Wavelength Narrowband Emissive Multi‐Resonance Delayed Fluorescence Emitters for Organic Light Emitting Diodes

Advanced Optical Materials, Journal Year: 2023, Volume and Issue: 11(22)

Published: Oct. 4, 2023

Abstract Over the past decade, thermally activated delayed fluorescence (TADF) emitters have garnered tremendous impetus because of their ability to harvest 100% excitons for light emission in organic emitting diodes (OLEDs). However, despite superior external quantum efficiencies (> 35%), broad spectra with associated full‐width‐at‐half maximum (FWHM > 70 nm) present a limiting factor that must be solved. Recently, multiple‐resonance TADF (MR‐TADF) materials based on heteroatom doped polyaromatic hydrocarbons gained astonishing attention owing remarkable narrowband < 30 nm). majority reported MR‐TADF falls blue/green region, which inevitably jeopardizes application full‐color OLEDs. Therefore, there is an urgent need develop new molecular designs expanding color‐gamut emitters, i.e., λ em 550 nm without compromising emission. To best current knowledge, no detailed reviews focusing different design strategies producing long‐wavelength been date. this end, review highlighting recent advances constructing presented, and photophysics OLED performance discussed. Finally, status future prospects are

Language: Английский

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Modulation of Carbazole/Phenol Resonant Partners within Diboron‐Based Multi‐Resonance Emitters Enable High‐Performance Narrowband Green to Red OLEDs

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: 34(28)

Published: March 10, 2024

Abstract Diboron‐based multi‐resonance (MR) molecules featuring para ‐B‐π‐B configuration represent a highly promising class of emitters for red and near‐infrared organic light‐emitting diodes (OLEDs). The emission spectra the diboron‐based MR can be fine‐tuned by modulating carbazole/phenol resonant partners. However, beyond spectral tuning, comprehensive understanding intricate relationship between molecular structure, overall properties remains elusive. In this work, through meticulous design precise material synthesis, study has constructed three new completed establishment family involving counterpart. These facilitate systematic investigation into impact partners on critical such as thermally activated delayed fluorescence, full‐width at half‐maximum, horizontal orientation ratio. Eventually, employing these emitters, high‐performance narrowband emitting OLEDs with maximum external quantum efficiencies (EQE max s) 30.2%, 33.0%, 37.0% are fabricated green, yellow, devices, respectively, together exceptional operational lifetimes. particular, both yellow exhibit unprecedented low‐efficiency roll‐off, maintaining high EQEs over 30% 25% ultrahigh brightness levels 10 000 100 cd m −2 , respectively.

Language: Английский

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Rigidity‐Enhanced Narrowband Iridium(III) Complexes with Finely‐Optimized Emission Spectra for Efficient Pure‐Red Electroluminescence

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

Published: March 24, 2024

Abstract Attaining phosphorescent materials with narrowband emission is crucial for advancing wide‐color‐gamut organic light‐emitting diode (OLED). Herein, a rigid modification strategy introduced iridium(III) complexes to achieve the red negligible 0–1 peak. By introducing indolo[3,2,1‐ jk ]carbazole (ICz) into cyclometalated ligand, Ir(III) complexes, ICziq‐Ir and ICzqz‐Ir, exhibit pure phosphorescence peaks at 608 613 nm full widths half‐maximum (FWHMs) of 37 38 (0.12 0.13 eV) in toluene, respectively. Furthermore, specific site ICzqz‐Ir greatly suppresses high‐frequency vibration structure, resulting photoluminescent spectrum close Gaussian distribution superior color purity. The OLEDs utilizing demonstrate maximum external quantum efficiencies 21.4 17.8% as well mild efficiency roll‐off. Remarkably, electroluminescence spectra similar FWHMs 43 CIE coordinates (0.65, 0.35) (0.66, 0.34), attesting excellent purity OLEDs.

Language: Английский

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Fused nonacyclic carbonyl/nitrogen-containing multi-resonance emitters with simultaneously redshifted and narrowed emission spectra for high-efficiency solution-processed OLEDs

Chemical Engineering Journal, Journal Year: 2025, Volume and Issue: unknown, P. 160102 - 160102

Published: Feb. 1, 2025

Language: Английский

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

Advanced Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 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

Language: Английский

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