Narrowband Emissive Thermally Activated Delayed Fluorescence Materials

Advanced Optical Materials, Год журнала: 2022, Номер 10(22)

Опубликована: Сен. 23, 2022

Abstract Organic thermally activated delayed fluorescence (TADF) materials have attracted significant research interest in the field of organic electronics because their inherent advantage 100% exciton utilization capability light‐emitting diodes (OLEDs) without use noble metals. However, despite high internal electroluminescence quantum efficiencies approaching unity, broad emission spectra with sizable full width at half maxima (FWHM; 60–100 nm) present a critical issue that must be solved for application ultrahigh‐definition OLED displays. Recently, new paradigm TADF featuring multiple resonance (MR) effect based on heteroatom‐doped polycyclic aromatic frameworks, referred to as MR‐TADF materials, has emerged and garnered considerable owing remarkable features efficient narrowband emissions extremely small FWHMs (≤30 nm). Currently, occupy prominent position cutting‐edge from both chemical physical perspectives. This review article focuses recent progress emissive systems perspective molecular design, photophysical properties, performance OLEDs. The current status future prospects this advanced material technology are discussed comprehensively.

Язык: Английский

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Chiral Multi‐Resonance TADF Emitters Exhibiting Narrowband Circularly Polarized Electroluminescence with an EQE of 37.2 %

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(30)

Опубликована: Май 10, 2022

Highly efficient circularly polarized luminescence (CPL) emitters with narrowband emission remain a formidable challenge for OLEDs (CP-OLEDs). Here, promising strategy developing chiral concurrently featuring multi-resonance thermally activated delayed fluorescence (MR-TADF) and electroluminescence (CPEL) is demonstrated by the integration of molecular rigidity, central chirality MR effect. A pair green denoted as (R)-BN-MeIAc (S)-BN-MeIAc designed. Benefited rigid quasi-planar MR-framework, enantiomers not only display mirror-image CPL spectra, but also exhibit TADF properties high photoluminescence quantum yield 96 %, narrow FWHM 30 nm, horizontal dipole orientation 90 % in doped film. Consequently, enantiomer-based CP-OLEDs achieved excellent external efficiencies 37.2 very low efficiency roll-off, representing highest device all reported CP-OLEDs.

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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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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Deep‐Blue Narrowband Hetero[6]helicenes Showing Circularly Polarized Thermally Activated Delayed Fluorescence Toward High‐Performance OLEDs

Advanced Materials, Год журнала: 2023, Номер 36(1)

Опубликована: Ноя. 14, 2023

Abstract Helicenes exhibit substantial potential as circularly polarized luminescence (CPL) active molecules. However, their application in organic light‐emitting diodes (CP‐OLEDs) is typically hindered by the challenge of integrating both high color purity and efficient triplet‐harvesting capability, particularly blue spectral region. Herein, a series hetero[6]helicene‐based emitters that strategically engineered through helical extension deep‐blue double‐boron‐based multiple resonance thermally activated delayed fluorescence (MR‐TADF) motif, introduced. Importantly, does not cause apparent structural deformation or perturb frontier molecular orbitals; thus, preserving emission MR‐TADF characteristics parent molecule. This approach also leads to reduced reorganization energy, resulting with narrower linewidth higher photoluminescence quantum yield. Further, motif enhances racemization barrier improved CPL performance dissymmetry factor values up 1.5 × 10 −3 . Exploiting these merits, devices incorporating chiral dopants demonstrate within Broadcast Service Television 2020 color‐gamut range, record external efficiencies (EQEs) 29.3%, have distinctive electroluminescence (CPEL) signals. Overall, authors’ findings underscore promising strategy for designing narrowband chiroptical materials advancing high‐definition displays.

Язык: Английский

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B,N‐Embedded Hetero[9]helicene Toward Highly Efficient Circularly Polarized Electroluminescence

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(18)

Опубликована: Фев. 21, 2024

The intrinsic helical π-conjugated skeleton makes helicenes highly promising for circularly polarized electroluminescence (CPEL). Generally, carbon undergo low external quantum efficiency (EQE), while the incorporation of a multi-resonance thermally activated delayed fluorescence (MR-TADF) BN structure has led to an improvement. However, reported B,N-embedded all show dissymmetry factors (g

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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The Golden Age of Thermally Activated Delayed Fluorescence Materials: Design and Exploitation

Chemical Reviews, Год журнала: 2024, Номер unknown

Опубликована: Дек. 12, 2024

Since the seminal report by Adachi and co-workers in 2012, there has been a veritable explosion of interest design thermally activated delayed fluorescence (TADF) compounds, particularly as emitters for organic light-emitting diodes (OLEDs). With rapid advancements innovation materials design, efficiencies TADF OLEDs each primary color points well white devices now rival those state-of-the-art phosphorescent emitters. Beyond electroluminescent devices, compounds have also found increasing utility applications numerous related fields, from photocatalysis, to sensing, imaging beyond. Following our previous review 2017 (

Язык: Английский

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Advances in organic materials for chiral luminescence-based OLEDs

Trends in Chemistry, Год журнала: 2023, Номер 5(10), С. 734 - 747

Опубликована: Сен. 15, 2023

Язык: Английский

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Quantitative prediction of rate constants and its application to organic emitters

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

Опубликована: Июнь 3, 2024

Many phenomena in nature consist of multiple elementary processes. If we can predict all the rate constants respective processes quantitatively, comprehensively and understand various phenomena. Here, report that it is possible to quantitatively related quantum yields without conducting experiments, using multiple-resonance thermally activated delayed fluorescence (MR-TADF) as an example. MR-TADFs are excellent emitters because its narrow emission, high luminescence efficiency, chemical stability, but they have one drawback: slow reverse intersystem crossing (RISC), leading efficiency roll-off reduced device lifetime. show a calculation method for obtaining yields. This study reveals strategy improve RISC compromising other important factors: radiative decay constants, photoluminescence yields, emission linewidths. Our be applied wide range research fields, providing comprehensive understanding mechanism including time evolution excitons.

Язык: Английский

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