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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Charge Transfer Excited State Promoted Multiple Resonance Delayed Fluorescence Emitter for High-Performance Narrowband Electroluminescence

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(23), С. 12550 - 12560

Опубликована: Июнь 5, 2023

Multiple resonance thermally activated delayed fluorescence (MR-TADF) emitters are promising candidates for narrowband organic light-emitting diodes, but their electroluminescent performance is typically hindered by the slow reverse intersystem crossing rate (kRISC). Herein, we present an effective strategy to introduce a multichannel (RISC) pathway with large spin-orbit coupling orthogonally linking electron-donating unit MR framework. Through delicate manipulation of excited-state energy levels, additional intersegmental charge transfer triplet state could be "silently" induced without perturbing character lowest excited singlet state. The proof-of-concept emitter CzBN3 not only affords 23-fold increase kRISC compared its prototypical skeleton also realizes close-to-unity photoluminescence quantum yield, radiative constant, and very narrow emission spectrum. These merits enable high maximum external efficiency (EQEmax) up 37.1% alleviated roll-off in sensitizer-free device (EQE1000 = 30.4%), further boost (EQEmax/1000 42.3/34.1%) realized hyperfluorescent device. state-of-the-art validates superiority our molecular design strategy.

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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Multiresonant TADF materials: triggering the reverse intersystem crossing to alleviate the efficiency roll-off in OLEDs

Chemical Communications, Год журнала: 2023, Номер 59(25), С. 3685 - 3702

Опубликована: Янв. 1, 2023

The hunt for narrow-band emissive pure organic molecules capable of harvesting both singlet and triplet excitons light emission has garnered enormous attention to promote the advancement light-emitting diodes (OLEDs). Over past decade, thermally activated delayed fluorescence (TADF) materials based on donor (D)/acceptor (A) combinations have been researched OLEDs in wide color gamut (RGB) regions. However, due strong intramolecular charge-transfer (CT) state, they exhibit broad with full-width-at-half maximum (FWHM) > 70 nm, which deviates from being detrimental achieving high purity future high-end display electronics such as high-definition TVs ultra-high-definition (UHDTVs). Recently, new development sub-class TADF emitters called multi-resonant (MR-TADF) boron/nitrogen atoms attracted much interest ultra-high definition OLEDs. Consequently, MR-TADF are appeal their potentiality promising candidates fabricating high-efficient numerous advantages photoluminescence quantum yield (PLQY), unprecedented purity, narrow bandwidth (FWHM ≤ 40 nm). Until now many developed ultra-gamut regions different design concepts. most MR-TADF-OLEDs showed ruthless external efficiency (EQE) roll-off characteristics at brightness. Such EQE were derived mainly low reverse intersystem crossing (kRISC) rate values. This feature article primarily focuses strategies improve kRISC some supportive including extending charge delocalization, heavy atom introduction, multi-donor/acceptor utilization, a hyperfluorescence system approach. Furthermore, outlook prospects developments skeletons described.

Язык: Английский

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Visible‐to‐UV Photon Upconversion: Recent Progress in New Materials and Applications

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(25)

Опубликована: Март 8, 2023

Ultraviolet (UV, λ<400 nm) light is essential for various photochemical reactions, but its intensity in the solar spectrum very low, and sources that artificially generate high-energy UV are inefficient environmentally unfriendly. A solution to this problem photon upconversion (UC) from visible (vis, λ>400 light. Among several mechanisms, UC based on triplet-triplet annihilation (TTA-UC) particular has made remarkable progress recent years. The development of new chromophores enabled highly efficient conversion low-intensity into In review, we summarize visible-to-UV TTA-UC, their production films application processes such as catalysis, bond activation polymerization. Finally, challenges opportunities future material applications will be discussed.

Язык: Английский

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NIR‐Absorbing B,N‐Heteroarene as Photosensitizer for High‐Performance NIR‐to‐Blue Triplet‐Triplet Annihilation Upconversion

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(25)

Опубликована: Апрель 18, 2023

Triplet-triplet annihilation upconversion (TTA-UC) with near-infrared (NIR) photosensitizers is highly desirable for a variety of emerging applications. However, the development NIR-to-blue TTA-UC large anti-Stokes shift extremely challenging because energy loss during intersystem crossing (ISC). Here, we develop first NIR-absorbing B,N-heteroarene-based sensitizer (BNS) multi-resonance thermally activated delayed fluorescence (MR-TADF) characters to achieve efficient TTA-UC. The small gap between singlet and triplet excited states (0.14 eV) BNS suppresses ISC loss, its long-delayed lifetime (115 μs) contributes transfer. As result, largest (1.03 among all heavy-atom-free NIR-activatable systems obtained high quantum yield 2.9 % (upper limit 50 %).

Язык: Английский

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A review of fused-ring carbazole derivatives as emitter and/or host materials in organic light emitting diode (OLED) applications

Materials Chemistry Frontiers, Год журнала: 2023, Номер 7(19), С. 4304 - 4338

Опубликована: Янв. 1, 2023

This review focuses on fused-ring carbazole derivatives, their molecular design, electronic and photophysical properties, applications as the emitter and/or host material in organic light emitting diodes (OLEDs).

Язык: Английский

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Recent progress and prospects of fluorescent materials based on narrow emission

Journal of Materials Chemistry C, Год журнала: 2023, Номер 11(20), С. 6471 - 6511

Опубликована: Янв. 1, 2023

MR-TADF emitters with narrow emission have been developed and are expected to become fourth-generation for HD-OLEDs, molecular design guidelines commercial prospects outlined in this review.

Язык: Английский

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Deep-blue organic light-emitting diodes for ultrahigh-definition displays

Nature Photonics, Год журнала: 2024, Номер 18(11), С. 1161 - 1169

Опубликована: Авг. 19, 2024

Язык: Английский

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Acceleration of reverse intersystem crossing in multi-resonance TADF emitter

Chem, Год журнала: 2024, Номер 10(5), С. 1485 - 1501

Опубликована: Фев. 15, 2024

Язык: Английский

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