Organoboron-based multiple-resonance emitters: synthesis, structure–property correlations, and prospects

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(3), P. 1624 - 1692

Published: Jan. 1, 2024

This review highlights organoboron-based multiple-resonance compounds’ synthetic strategies classified as one-pot borylation, one-shot and late-stage functionalisation, explores material structure–photophysical property correlations.

Language: Английский

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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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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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Advancing Triplet Exciton Harvesting Through Heavy Atom Selenium Manipulation in Multiple Resonance Thermally Activated Delayed Fluorescent Emitters

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

Published: April 21, 2024

Abstract In the development of organic light‐emitting diodes (OLEDs) with high efficiency and minimal roll‐off, fast reverse intersystem crossing (RISC) in multi‐resonance thermally activated delayed fluorescence (MR‐TADF) materials is critical. The RISC process typically hindered by insufficient spin‐orbital coupling (SOC). Incorporating heavy atom selenium into MR‐TADF structure has potential to enhance SOC through effect. However, specific placement within molecule results different enhancements SOC, detailed interplay between these factors yet be elucidated. introduction a selenium‐containing moiety, phenoxaselenine, at substituted positions undertaken, revealing that 3‐substituted phenoxaselenine exhibits faster transition significant increase higher triplet excited states S 1 state, compared 2‐substituted phenoxaselenine. Significantly reduced roll‐off achieved for narrow‐band emission OLEDs based on owing enhanced effect, giving an impressive external quantum above 20% even under 10 000 cd m −2 corresponding OLED device. These underscore strategic effect manipulation efficient spin‐flipping.

Language: Английский

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Nitrogen‐Embedding Strategy for Short‐Range Charge Transfer Excited States and Efficient Narrowband Deep‐Blue Organic Light Emitting Diodes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(35)

Published: June 3, 2024

The development of deep-blue organic light-emitting diodes (OLEDs) featuring high efficiency and narrowband emission is great importance for ultrahigh-definition displays with wide color gamut. Herein, based on the nitrogen-embedding strategy modifying short range charge transfer excited state energies multi-resonance (MR) thermally activated delayed fluorescence (TADF) emitters, we introduce one or two nitrogen atoms into central benzene ring a versatile boron-embedded 1,3-bis(carbazol-9-yl)benzene skeleton. This approach resulted in stabilization highest occupied molecular orbital energy levels formation intramolecular hydrogen bonds, thus systematic hypsochromic shifts narrowing spectra. In toluene solution, heterocyclic-based MR-TADF molecules, Py-BN Pm-BN, exhibit emissions photoluminescence quantum yields 93 % 94 %, narrow full width at half maximum 14 13 nm, respectively. A hyperfluorescent OLED exhibited external 27.7 desired purity Commission Internationale de L'Eclairage (CIE) coordinates (0.150, 0.052). These results demonstrate significant potential deep blue emitters.

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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An Efficient Ultra‐Narrowband Yellow Emitter Based on a Double‐Boron‐Embedded Tetraazacyclophane

Angewandte Chemie International Edition, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 3, 2025

Abstract Ultra‐narrowband and highly modifiable multiple resonance thermally activated delayed fluorescence (MR‐TADF) materials are crucial for realizing high‐performance wide‐color‐gamut display applications. Despite progress, most MR‐TADF emitters remain confined to blue green wavelengths, with difficulties extending into longer wavelengths without significant spectral broadening, which compromises color purity in full‐color organic light‐emitting diode (OLED) displays. In this work, we present a novel tetraazacyclophane‐based architecture embedding dual boron atoms remarkedly enhance intramolecular charge transfer through the strategic positioning of nitrogen atoms. This arrangement induces substantial redshift while maintaining structural rigidity molecular orbital symmetry, hole‐electron central distance 0 Å, allowing ultra‐narrowband emission. The resulting material, HBN , delivers yellow emission peaking at 572 nm (2.168 eV) an impressively narrow full‐width half‐maximum (FWHM) 17 (0.064 dilute toluene. Moreover, corresponding phosphorescent‐sensitized OLED achieves maximum 581 nm, FWHM 25 high external quantum efficiency 36.1 %, luminance exceeding 40,000 cd m −2 . These outstanding photoluminescent electroluminescent performances validate superiority our design strategy, highlighting its potential cutting‐edge optoelectronic

Language: Английский

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A Quadruple‐Borylated Multiple‐Resonance Emitter with para/meta Heteroatomic Patterns for Narrowband Orange‐Red Emission

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(35)

Published: July 11, 2023

Hindered by spectral broadening issues with redshifted emission, long-wavelength (e.g., maxima beyond 570 nm) multiple resonance (MR) emitters full width at half (FWHMs) below 20 nm remain absent. Herein, strategically embedding diverse boron (B)/nitrogen (N) atomic pairs into a polycyclic aromatic hydrocarbon (PAH) skeleton, we propose hybrid pattern for the construction of narrowband MR emitter. The proof-of-concept emitter B4N6-Me realized orange-red emission an extremely small FWHM 19 (energy unit: 70 meV), representing narrowest among all reported emitters. Theoretical calculations revealed that cooperation applied para B-π-N and B-π-B/N-π-N patterns is complementary, which gives rise to both redshift characteristics. corresponding organic light-emitting diode (OLED) employing achieved state-of-the-art performance, e.g., 27 99 excellent maximum external quantum efficiency (EQE) 35.8 %, ultralow roll-off (EQE 28.4 % 1000 cd m-2 ). This work provides new insights further molecular design synthesis

Language: Английский

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Combining Carbazole Building Blocks and ν‐DABNA Heteroatom Alignment for a Double Boron‐Embedded MR‐TADF Emitter with Improved Performance

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(32)

Published: June 13, 2023

Building blocks and heteroatom alignments are two determining factors in designing multiple resonance (MR)-type thermally activated delayed fluorescence (TADF) emitters. Carbazole-fused MR emitters, represented by CzBN derivatives, the of ν-DABNA star series MR-TADF emitters that show impressive performances from aspects building alignments, respectively. Herein, a novel analog, Π-CzBN, featuring alignment is developed via facile one-shot lithium-free borylation. Π-CzBN exhibits superior photophysical properties with photoluminescence quantum yield close to 100 % narrowband sky blue emission full width at half maximum (FWHM) 16 nm/85 meV. It also gives efficient TADF small singlet-triplet energy offset 40 meV fast reverse intersystem crossing rate 2.9×105 s-1 . The optimized OLED using as emitter achieves an exceptional external efficiency 39.3 low roll-off 20 1000 cd m-2 495 nm FWHM 21 nm/106 meV, making it one best reported devices based on comprehensive performance.

Language: Английский

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B−N/B−O Contained Heterocycles as Fusion Locker in Multi‐Resonance Frameworks towards Highly‐efficient and Stable Ultra‐Narrowband Emission

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(45)

Published: Aug. 16, 2023

Fusing condensed aromatics into multi-resonance (MR) frameworks has been an exquisite strategy to modulate the optoelectronic properties, which, however, always sacrifices small full width at half maxima (FWHM). Herein, we strategically embed B-N/B-O contained heterocycles as fusion locker classical MR prototypes, which could enlarge π-extension and alleviate steric repulsion for enhanced planar skeleton suppress high-frequency stretching/ scissoring vibrations ultra-narrowband emissions. Sky-blue emitters with extremely FWHMs of 17-18 nm are thereafter obtained targeted emitters, decreased by (1.4-1.9)-fold compared prototypes. Benefiting from their high photoluminescence quantum yields >90 % fast radiative decay rates >108 s-1 , one those shows a maximum external efficiency 31.9 in sensitized devices, remains 25.8 practical luminance 1,000 cd m-2 FWHM merely 19 nm. Notably long operation half-lifetime 1,278 h is also recorded same device, representing longest lifetimes among sky-blue devices based on emitters.

Language: Английский

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