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

Chemical Society Reviews, Год журнала: 2024, Номер 53(3), С. 1624 - 1692

Опубликована: Янв. 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.

Язык: Английский

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

Advanced Science, Год журнала: 2023, Номер 10(28)

Опубликована: Авг. 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.

Язык: Английский

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Constructing Highly Efficient Circularly Polarized Multiple‐Resonance Thermally Activated Delayed Fluorescence Materials with Intrinsically Helical Chirality

Advanced Materials, Год журнала: 2023, Номер 35(42)

Опубликована: Июль 18, 2023

Abstract Advanced circularly polarized multiple‐resonance thermally activated delayed fluorescence (CP‐MR‐TADF) materials synergize the advantages of luminescence (CPL), narrowband emission, and TADF characteristic, which can be fabricated into highly efficient organic light‐emitting diodes (CP‐OLEDs) with high color purity, directly facing urgent market strategic demand ultrahigh‐definition 3D displays. In this work, based on an edge‐topology molecular‐engineering (ETME) strategy, a pair high‐performance CP‐MR‐TADF enantiomers, ( P M )‐BN‐Py, is developed, merges intrinsically helical chirality MR framework. The optimized CP‐OLEDs )‐BN‐Py emitters newly developed ambipolar transport host PhCbBCz exhibit pure green emission sharp peaks 532 nm, full‐width at half‐maximum (FWHM) 37 Commission Internationale de L'Eclairage (CIE) coordinates (0.29, 0.68). Importantly, they achieve remarkable maximum external quantum efficiencies (EQEs) 30.6% 29.2%, clear electroluminescence (CPEL) signals dissymmetry factors g EL s) −4.37 × 10 −4 +4.35 for respectively.

Язык: Английский

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Highly efficient pure-blue organic light-emitting diodes based on rationally designed heterocyclic phenophosphazinine-containing emitters

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Июль 22, 2024

Abstract Multi-resonance thermally activated delayed fluorophores have been actively studied for high-resolution photonic applications due to their exceptional color purity. However, these compounds encounter challenges associated with the inefficient spin-flip process, compromising device performance. Herein, we report two pure-blue emitters based on an organoboron multi-resonance core, incorporating a conformationally flexible donor, 10-phenyl-5 H -phenophosphazinine 10-oxide (or sulfide). This design concept selectively modifies orbital type of high-lying excited states charge transfer configuration while simultaneously providing necessary conformational freedom enhance density without sacrificing We show that different embedded phosphorus motifs (phosphine oxide/sulfide) donor can finely tune electronic structure and freedom, resulting in accelerated process through intense spin-vibronic coupling, achieving over 20-fold increase reverse intersystem crossing rate compared parent emitter. Utilizing emitters, achieve high-performance organic light-emitting diodes, showcasing top-tier external quantum efficiency 37.6% reduced roll-offs. proposed strategy not only conventional notion electron-donors are undesirable constructing narrowband but also offer pathway designing efficient narrow-spectrum blue diodes.

Язык: 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, Год журнала: 2024, Номер 63(35)

Опубликована: Июнь 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.

Язык: Английский

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Recent Advances in Narrow Emission Bandwidth Materials for Application in Organic Light‐Emitting Diodes

Advanced Optical Materials, Год журнала: 2025, Номер unknown

Опубликована: Фев. 21, 2025

Abstract The preparation of narrow emission bandwidth materials is crucial for the development advanced organic light‐emitting diodes (OLEDs). In this review article, state‐of‐the‐art methodologies used emitters with high color purity are summarized, and favorable design strategies rationally organized. Currently OLEDs have some issues, such as device stabilization that must be resolved, should also considered. Given recent exponential growth in number types narrowband emissive organometallic complexes exhibiting multiple‐resonance thermally activated delayed fluorescence metal‐to‐ligand charge transfer characteristics, there an urgent need to establish key technology descriptors purity. review, developments boron, fused indolocarbazole, carbonyl, phosphine oxide, exhibit spectra described, future directions advance performance devices suggested.

Язык: Английский

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Frontier Molecular Orbital Engineering: Constructing Highly Efficient Narrowband Organic Electroluminescent Materials

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(52)

Опубликована: Сен. 19, 2023

Abstract It is of great strategic significance to develop highly efficient narrowband organic electroluminescent materials that can be utilized manufacture ultra‐high‐definition (UHD) displays and meet or approach the requirements Broadcast Television 2020 (B.T.2020) color gamut standards. This motif poses challenges for molecular design synthesis, especially developing generality, diversity, scalability, robustness structures. The emergence multiple resonance thermally activated delayed fluorescence (MR‐TADF) emitters has ingeniously solved problems demonstrated bright application prospects in field UHD displays, sparking a research boom. Minireview summarizes endeavors materials, with emphasis on tremendous contribution frontier orbital engineering (FMOE) strategy. combines outstanding advantages MR framework donor‐acceptor (D−A) structure, achieve red‐shift emission simultaneously, which development long‐wavelength maxima exceeding 500 nm. We hope this would provide some inspiration what could transpire future.

Язык: 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, Год журнала: 2023, Номер 62(32)

Опубликована: Июнь 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.

Язык: Английский

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Narrowband Near‐Infrared Multiple‐Resonance Thermally Activated Delayed Fluorescence Emitters towards High‐Performance and Stable Organic Light‐Emitting Diodes

Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(7)

Опубликована: Дек. 27, 2023

Multiple-resonance thermally activated delayed fluorescence (MR-TADF) materials are highly coveted for their high efficiency and narrowband emission in organic light-emitting diodes (OLEDs). Nevertheless, the development of near-infrared (NIR) MR-TADF emitters remains a formidable challenge. In this study, we design two new NIR emitters, PXZ-R-BN BCz-R-BN, by embedding 10H-phenoxazine (PXZ) 7H-dibenzo[c,g]carbazole (BCz) fragments to increase electron-donating ability or extending π-conjugation on framework para-boron fusing polycyclic aromatic hydrocarbons (PAHs). Both compounds emit region, with full-width at half-maximum (FWHM) 49 nm (0.13 eV) 43 (0.11 BCz-R-BN toluene. To sensitize OLEDs, platinum complex, Pt-1, is designed as sensitizer. The PXZ-R-BN-based sensitized OLEDs achieve maximum external quantum (EQE

Язык: 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, Год журнала: 2023, Номер 62(45)

Опубликована: Авг. 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.

Язык: Английский

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