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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High‐Efficiency Narrowband Multi‐Resonance Emitter Fusing Indolocarbazole Donors for BT. 2020 Red Electroluminescence and Ultralong Operation Lifetime

Advanced Materials, Год журнала: 2023, Номер 35(30)

Опубликована: Апрель 19, 2023

Polycyclic heteroaromatics with multi-resonance (MR) characteristics are attractive materials for narrowband emitters in wide-color-gamut organic light-emitting diodes. However, MR pure-red colors still rare and usually exhibit problematic spectral broadening when redshifting emission. Here, a emitter is reported by fusing indolocarbazole segments into boron/oxygen-embedded skeleton, realizing BT.2020 red electroluminescence the first time together high efficiency an ultralong lifetime. The rigid segment possesses strong electron-donating ability due to its para-positioned nitrogen-π-nitrogen backbone also enlarges π-extension of skeleton suppress structural displacement during radiation, achieving concurrently redshifted narrowed emission spectrum. An maximum at 637 nm full width half-maxima merely 32 (0.097 eV) recorded toluene. corresponding device simultaneously exhibits CIE coordinates (0.708, 0.292) precisely matching point, external quantum 34.4% low roll-off LT95 (time 95% initial luminance) >10 000 h 1000 cd m-2 . These performance superior even those state-of-the-art perovskite quantum-dot-based devices this specific color, paving way toward practical applications.

Язык: Английский

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High‐Performance Multi‐Resonance Thermally Activated Delayed Fluorescence Emitters for Narrowband Organic Light‐Emitting Diodes

Advanced Functional Materials, Год журнала: 2023, Номер 33(50)

Опубликована: Авг. 7, 2023

Abstract Multi‐resonance thermally activated delayed fluorescence (MR‐TADF) emitters have drawn considerable attention because of their remarkable optoelectronic properties high emission efficiency and narrow profile, represent an active subject cutting‐edge research in the organic electroluminescence (EL). However, slow reverse intersystem crossing (RISC) rate MR‐TADF emitter caused by large energy gap (Δ E ST ) small spin‐orbit coupling (SOC) matrix elements between singlet triplet excited states limits further development EL devices. Currently, innovative molecular design strategies been developed including heavy atom integration, π‐extended MR framework metal perturbation, so on to improve RISC process for high‐performance Here, overview is presented recent progress with fast ( > 10 −5 s −1 ), particular design, properties, device performance light‐emitting diodes (OLEDs), which intends systematize knowledge this thriving highly efficient emitters. Finally, challenges future prospects materials are discussed comprehensively.

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

Advanced Materials, Год журнала: 2023, Номер 36(5)

Опубликована: Сен. 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

Язык: Английский

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A Simple Molecular Design Strategy for Pure‐Red Multiple Resonance Emitters

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(20)

Опубликована: Март 15, 2023

Though the flourishment of materials with multiple resonance (MR) in blue to green regions, red-emissive MR emitters are still rare literatures, which definitely should be resolved for further applications. Herein, we report a simple molecular design strategy construction pure-red by conjugate charge transfer, could greatly enhance π-conjugation degree and charge-transfer property target molecule while maintaining basic feature MR, leading significant redshift more than 128 nm compared selected parent core. The proof-of-concept emitter PPZ-BN exhibited emission dominant peak at 613 small full-width-at-half-maximum 0.16 eV (48 nm). optimized organic light-emitting diode showed high external quantum efficiency 26.9 %, roll-off, an excellent operation stability (LT99) 43 hours initial luminance 10 000 cd m-2 .

Язык: Английский

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Multi‐Resonance Building‐Block‐Based Electroluminescent Material: Lengthening Emission Maximum and Shortening Delayed Fluorescence Lifetime

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(27)

Опубликована: Апрель 29, 2023

Multi-resonance thermally activated delayed fluorescence (MR-TADF) materials are considered a class of organic with exceptional electronic and optical properties, which make them promising for the applications in light-emitting diodes (OLEDs). In this study, we improved, synthesized, characterized multiple-resonance type emitter based on assembly MR-building blocks (MR-BBs). By optimizing geometric arrangement MR-BBs, were able to generate narrowband emission longer wavelength region shorten excited-state lifetime, resulting improved efficiency compared parent molecule. Our proof-of-concept molecule, m-DBCz, exhibited yellowish-green TADF full width at half-maximum 32 nm small singlet-triplet energy gap 0.04 eV. The OLED developed using m-DBCz as demonstrated electroluminescence 548 achieved high external quantum (EQE) 34.9 %. Further optimization device resulted 36.3 % extremely low roll-off, EQE values 30.1 27.7 obtained even luminance levels 50 000 100 cd m-2 . These results demonstrate potential MR-TADF ultrahigh-luminance OLEDs.

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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“Core–Shell” Wave Function Modulation in Organic Narrowband Emitters

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(27), С. 18331 - 18340

Опубликована: Июнь 20, 2024

Efficient red–green–blue primary luminescence with an extraordinarily narrow band and durability is crucial for advanced display applications. Recently, the emergence of multiple-resonance (MR) from short-range atomic interactions has been shown to induce extremely spectral widths in pure organic emitters. However, achieving wide-range color tuning without compromising purity remains a persistent challenge MR Herein, concept electronic donor/acceptor "core–shell" modulation proposed within boron/nitrogen (B/N) skeleton, enabling rational utilization intramolecular charge transfer facilitate wavelength shift. The dense B atoms localized at center molecule effectively compress electron density stabilize lowest unoccupied molecular orbital wave function. This electron-withdrawing core embedded peripheral electron-donating atoms. Consequently, doping single atom into deep-blue framework led profound bathochromic shift 447 624 nm (∼0.8 eV) while maintaining width 0.10 eV this pure-red emitter. Notably, light-emitting diodes assisted by thermally activated delayed fluorescence molecules achieved superb electroluminescent stability, LT99 (99% initial luminance) exceeding 400 h luminance 1000 cd m–2, approaching commercial-level performance assistance phosphors.

Язык: Английский

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Sulfur-locked multiple resonance emitters for high performance orange-red/deep-red OLEDs

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Янв. 2, 2025

Язык: Английский

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