Blue TADF Conjugated Polymers with Multi‐Resonance Feature toward Solution‐Processable Narrowband Blue OLEDs

Advanced Functional Materials, Год журнала: 2023, Номер 34(6)

Опубликована: Окт. 25, 2023

Abstract The development of thermally activated delayed fluorescence (TADF) polymers with narrowband emission, particularly in the blue region, remains a formidable challenge. Herein, new approach is demonstrated for TADF conjugated by integrating multiresonance moiety into backbone. All exhibit characteristics emission full‐width at half‐maximums (FWHMs) 23 nm. solution‐processed OLEDs based on these achieve maximum external quantum efficiency (EQE max ) 17.9% peak 479 nm and FWHM 28 main‐chain type MR‐TADF polymer shed light emissive polymers.

Язык: Английский

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Recent Progress of Thermally Activated Delayed Fluorescent Materials with Narrowband Red, Green, and Blue (RGB) Emission

ACS Materials Letters, Год журнала: 2024, Номер 6(5), С. 1746 - 1768

Опубликована: Апрель 2, 2024

Narrowband thermally activated delayed fluorescence (TADF) materials have received widespread attention due to their promising applications in organic light-emitting diodes with high-definition displays. Great efforts been done achieve full-color narrowband emissions donor–acceptor (D–A) and multiple-resonance (MR) TADF materials. In comparison the D–A materials, MR-based basically showed smaller full width at half-maximum (fwhm) of spectra owing inherent structural vibration inhibition electronic transition characteristics. Herein, review summarizes current research progress on both MR blue, green red emission regions fwhm less than 70 nm concentrating molecular design strategies, photophysical properties corresponding device performance, proposes some possible future topic. This aims give physical insight structure–property relationship such offer guidance for further developing provide a structured database platform high-throughput or machine learning research.

Язык: Английский

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Peripheral Selenium Modification of Multi‐Resonance Thermally Activated Delayed Fluorescence Molecules for High‐Performance Blue Organic Light‐Emitting Diodes

Advanced Optical Materials, Год журнала: 2024, Номер 12(11)

Опубликована: Фев. 28, 2024

Abstract Multi‐resonance thermally activated delayed fluorescence (MR‐TADF) molecules have attracted much attention in the academia owing to their unique photoelectrical properties. However, MR‐TADF emitters usually show slow reverse intersystem crossing (RISC) rate, resulting high efficiency roll‐off of organic light‐emitting diodes (OLEDs) and seriously limiting further development. Here, a peripheral selenium (Se) modification is presented for promote RISC process while keeping narrowband emission high‐performance blue OLEDs. Compared parent (NBN t BuNBN), SeNBN Se BuNBN exhibited narrower full‐width at half maximum (FWHM) value 23 nm more obvious properties with up 86%, shorter lifetime 2.4 µs as well faster rate 3.34×10 5 s −1 . Therefore, OLEDs based on these two modified are achieved external quantum (EQE) 25.5% extremely suppressed roll‐offs 3.9% 100 cd m −2 24.4% 1000 This work demonstrated that introduction atom can achieve semiconductors both fast constant optoelectronic devices.

Язык: Английский

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Modulating electronic confinement and structural distortion of multiple resonance emitters enables high-performance ultrapure blue OLED

Chemical Engineering Journal, Год журнала: 2024, Номер 482, С. 148876 - 148876

Опубликована: Янв. 17, 2024

Язык: Английский

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Secondary donor-acceptor group enable efficient pure green organic light-emitting devices based on multi-resonance TADF emitters

Chemical Engineering Journal, Год журнала: 2024, Номер 481, С. 148794 - 148794

Опубликована: Янв. 14, 2024

Язык: Английский

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Peripheral Substitution Engineering of MR‐TADF Emitters Embedded With B‒N Covalent Bond Towards Efficient BT.2020 Blue Electroluminescence

Advanced Materials, Год журнала: 2024, Номер unknown

Опубликована: Окт. 15, 2024

Compared with the classical boron/nitrogen (B/N) doped ones, multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters embedded B-N covalent bond behave a significantly blue-shifted narrowband TADF, and thus show greater potential in ultrapure blue organic light-emitting diodes (OLEDs). As proof of concept, herein peripheral substitution engineering is demonstrated based on such B‒N parent core. The simple approach found to ensure easy synthesis via one-pot lithium-free borylation-annulation, manipulate excited states through different electronic coupling between core substituent, introduce steric hindrance minimize unwanted spectral broadening. Impressively, OLEDs are realized give high external quantum efficiency 20.3% together Commission Internationale de l'Éclairage coordinates (0.152, 0.046). performance well competent those B/N MR-TADF emitters, clearly highlighting that framework novel promising paradigm towards efficient BT.2020 standard.

Язык: Английский

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Boron‐ and Oxygen‐Doped π‐Extended Helical Nanographene with Circularly Polarised Thermally Activated Delayed Fluorescence

Chemistry - A European Journal, Год журнала: 2024, Номер 30(19)

Опубликована: Янв. 25, 2024

Abstract Helical nanographenes have garnered substantial attention owing to their finely adjustable optical and semiconducting properties. The strategic integration of both helicity heteroatoms into the nanographene structure, facilitated by a boron‐oxygen‐based multiple resonance (MR) thermally activated delayed fluorescence (TADF), elevates its photophysical chiroptical features. This signifies introduction an elegant category helical that combines (TADF) (CPL) In this direction, we report synthesis, optical, properties boron, oxygen‐doped Π‐extended nanographene. π‐extension induces distortion in DOBNA‐incorporated nanographene, endowing pair helicenes, ( P)‐ B2NG , M)‐ exhibiting circularly polarized luminescence with g lum −2.3×10 −3 +2.5×10 respectively. exhibited MR‐TADF lifetime below 5 μs, reasonably high quantum yield (50 %). Our molecular design enriches opens up new opportunities multidisciplinary fields.

Язык: Английский

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Structural Optimization of BODIPY Derivatives: Achieving Stable and Long-Lived Green Emission in Hyperfluorescent OLEDs

ACS Applied Materials & Interfaces, Год журнала: 2024, Номер 16(17), С. 22274 - 22281

Опубликована: Апрель 23, 2024

Boron dipyrromethene (BODIPY) derivatives are widely studied as terminal emitters in organic light-emitting diodes (OLED) due to their narrow emission and high photoluminescence quantum yield (PLQY). However, the strategy for precisely tuning toward a color purity is still challenging. Herein, we developed new design regulate of BODIPY by modifying electronic steric dominance using functionalities, such nitrile, pentafluorophenyl, diethyl, monobenzyl. These rational modifications yielded series four novel green emitters, namely, tPN-BODIPY, tPPP-BODIPY, tPBn-BODIPY, tPEN-BODIPY, each benefited with tuned emissions range 517 542 nm fwhm 25 up 96%. Among these synthesized BODIPYs, an unsymmetrical tPBn-BODIPY was chosen final dopant (FD) explore its application OLED devices. The fabricated TADF sensitized fluorescence-OLED (TSF-OLED) exhibits band pure at 531 corresponding CIE coordinates (x, y) = (0.27, 0.68) maximum external efficiency (EQE) 20%. Furthermore, TSF-OLED displayed exceptionally prolonged device operational lifetime (LT90) 210 h initial luminescence 3000 cd m–2.

Язык: Английский

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Enhancing Spin–Orbit Coupling in an Indolocarbazole Multiresonance Emitter by a Sulfur‐Containing Peripheral Substituent for a Fast Reverse Intersystem Crossing

Advanced Materials, Год журнала: 2024, Номер unknown

Опубликована: Сен. 17, 2024

Abstract A fast reverse intersystem crossing (RISC) remains an ongoing pursuit for multiresonance (MR) emitters but faces formidable challenges, particularly indolocarbazole (ICz) derived ones. Here, heavy‐atom effect is introduced first to construct ICz‐MR emitter using a sulfur‐containing substitute, simultaneously enhancing both spin–orbit and spin–vibronic coupling afford RISC with rate of 1.2 × 10 5 s −1 , nearly one order magnitude higher than previous maximum values. The also exhibits extremely narrow deep‐blue emission peaking at 456 nm full‐width half‐maxima merely 12 photoluminescence quantum yield 92%. Benefiting from its efficient triplet upconversion capability, this achieves not only high external efficiency (EQE) 31.1% in organic light‐emitting diodes greatly alleviates roll‐off, affording record‐high EQEs 29.9% 1000 cd m −2 18.7% 5000 among devices emitters.

Язык: Английский

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Multi‐π‐Stacked Through‐Space Charge‐Transfer Emitters with Accelerated Radiative Decay for High‐Efficiency Organic Light‐Emitting Diodes with Suppressed Efficiency Roll‐Offs

Advanced Functional Materials, Год журнала: 2025, Номер unknown

Опубликована: Янв. 7, 2025

Abstract Through‐space charge‐transfer (TSCT) thermally‐activated delayed fluorescence (TADF) emitters have been extensively explored for organic light‐emitting diodes (OLEDs), but their low radiative decay rates ( k r,s ) remained a formidable obstacle to enhancement of luminescent efficiency (Ф PL and suppression roll‐off the OLED. Here, multi‐π‐stacked TSCT‐TADF with accelerated are developed 3D [fixed acceptor]/donor/[fixed acceptor] structure formed on two individual fluorene bridges. Single‐crystal structures theoretical calculations reveal cis or trans ‐configurations acceptors around central donor double TSCT channels in emitter. In doped films, show green‐blue TADF high up 1.1 × 10 7 s −1 near‐unity Ф , which notably improved compared single‐π‐stacked analog = 2.1 6 0.89). OLEDs based external quantum efficiencies (EQEs) 26.2% EQEs at 1000 cd m −2 (EQE remain 23.4%, superior over device max /EQE 20%/15.6%). A narrowband blue‐green OLED one emitter as sensitizer shows EQE 37.6%/27.7%. The work demonstrates great potential enhancing high‐efficiency roll‐offs.

Язык: Английский

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