Realizing efficient blue and deep-blue delayed fluorescence materials with record-beating electroluminescence efficiencies of 43.4% DOI Creative Commons
Yan Fu, Hao Liu, Ben Zhong Tang

et al.

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: April 10, 2023

As promising luminescent materials for organic light-emitting diodes (OLEDs), thermally activated delayed fluorescence are booming vigorously in recent years, but robust blue ones still remain challenging. Herein, we report three highly efficient and deep-blue comprised of a weak electron acceptor chromeno[3,2-c]carbazol-8(5H)-one with rigid polycyclic structure donor spiro[acridine-9,9'-xanthene]. They hold distinguished merits excellent photoluminescence quantum yields (99%), ultrahigh horizontal transition dipole ratios (93.6%), fast radiative reverse intersystem crossing, which furnish superb electroluminescence Commission Internationale de I'Eclairage coordinates (CIEx,y) (0.14, 0.18) 0.15) record-beating external efficiencies (ηexts) 43.4% 41.3%, respectively. Their efficiency roll-offs successfully reduced by suppressing triplet-triplet singlet-singlet annihilations. Moreover, high-performance green hyperfluorescence OLEDs achieved utilizing these as sensitizers multi-resonance dopants, providing state-of-the-art ηexts 32.5% (CIEx,y = 0.14, 0.10) 37.6% 0.32, 0.64), respectively, well greatly advanced operational lifetimes. These splendid results can surely inspire the development devices.

Language: Английский

Recent Advances in Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds DOI Creative Commons
Arseni Borissov, Yogesh Kumar Maurya, Liliia Moshniaha

et al.

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(1), P. 565 - 788

Published: Dec. 1, 2021

This review surveys recent progress in the chemistry of polycyclic heteroaromatic molecules with a focus on structural diversity and synthetic methodology. The article covers literature published during period 2016-2020, providing an update to our first this topic (

Language: Английский

Citations

429
Recent advances in organic luminescent materials with narrowband emission DOI Creative Commons

Jung Min Ha,

Seon Hyoung Hur,

Ambika Pathak

et al.

NPG Asia Materials, Journal Year: 2021, Volume and Issue: 13(1)

Published: July 16, 2021

Abstract The International Telecommunication Union announced a new color gamut standard of broadcast service television (BT 2020) for ultra-high-definition TV in 2012. To satisfy the wide-color BT 2020, monochromatic red (R), green (G), and blue (B) emissions require small full width at half-maximum, which is an important property improving purity. Although organic light-emitting diode (OLED) displays are currently one main types display technologies, their broad emission via strong vibronic coupling between ground excited states major hurdle to overcome development next-generation displays. Thus, OLED emitters with narrowband R–G–B great significance. In this review, recent progress materials summarized by grouping them into fluorescent, phosphorescent, thermally activated delayed fluorescent reveal correlation molecular structures, optical properties, device characteristics. We discuss rational design strategies achieve narrow photoluminescence electroluminescence underlying mechanisms controlling bandwidth. Finally, challenges realization future prospects such devices discussed.

Language: Английский

Citations

347
Quenching‐Resistant Multiresonance TADF Emitter Realizes 40% External Quantum Efficiency in Narrowband Electroluminescence at High Doping Level DOI
Pengcheng Jiang, Jingsheng Miao, Xiaosong Cao

et al.

Advanced Materials, Journal Year: 2021, Volume and Issue: 34(3)

Published: Nov. 12, 2021

Multiresonance thermally activated delayed fluorescence (MR-TADF) emitters manifest great potential for organic light-emitting diodes (OLEDs) due to their high exciton-utilization efficiency and narrowband emission. Nonetheless, tendency toward self-quenching caused by strong interchromophore interactions would induce doping sensitivity deteriorate the device performances, effective strategy construct quenching-resistant without sacrifycing color purity is still be developed. By segregating planar MR-TADF skeleton using two bulky carbazolyl units, herein a highly emissive molecule with enhanced quenching resistance reported. The steric effect largely removes formation of detrimental excimers/aggregates, boosts performance corresponding devices maximum external quantum (EQEmax ) up 40.0% full width at half (FWHM) 25 nm, representative only example single OLED that can concurrently achieve narrow bandwidth EL surpassing 40% date. Even ratio 30 wt%, EQEmax retained 33.3% nearly unchanged emission spectrum. This work provides viable approach realize doping-insensitive extreme high-end displays.

Language: Английский

Citations

345
Narrowband Emissive Thermally Activated Delayed Fluorescence Materials DOI Creative Commons
Hyung Jong Kim, Takuma Yasuda

Advanced Optical Materials, Journal Year: 2022, Volume and Issue: 10(22)

Published: Sept. 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.

Language: Английский

Citations

293
Highly Efficient Electroluminescence from Narrowband Green Circularly Polarized Multiple Resonance Thermally Activated Delayed Fluorescence Enantiomers DOI
Yincai Xu, Qingyang Wang, Xinliang Cai

et al.

Advanced Materials, Journal Year: 2021, Volume and Issue: 33(21)

Published: April 17, 2021

Abstract Purely organic fluorescent materials that concurrently exhibit high efficiency, narrowband emission, and circularly polarized luminescence (CPL) remain an unaddressed issue despite their promising applications in wide color gamut‐ 3D‐display. Herein, the CPL optical property multiple resonance (MR) effect induced thermally activated delayed fluorescence (MR‐TADF) emission are integrated with purity luminous efficiency together. Two pairs of highly efficient green CP‐MR‐TADF enantiomers, namely, ( R / S )‐OBN‐2CN‐BN )‐OBN‐4CN‐BN, developed. The enantiomer‐based light‐emitting diodes (OLEDs) pure narrow full‐width at half‐maximums (FWHMs) 30 33 nm, maximum external quantum efficiencies (EQEs) 29.4% 24.5%, clear electroluminescence (CPEL) signals dissymmetry factors g EL ) +1.43 × 10 −3 /−1.27 +4.60 −4 /−4.76 , respectively. This is first example a OLED exhibits CPEL signal, TADF concurrently.

Language: Английский

Citations

256
Achieving Ultimate Narrowband and Ultrapure Blue Organic Light‐Emitting Diodes Based on Polycyclo‐Heteraborin Multi‐Resonance Delayed‐Fluorescence Emitters DOI Creative Commons
In Seob Park,

Minlang Yang,

Hiromoto Shibata

et al.

Advanced Materials, Journal Year: 2021, Volume and Issue: 34(9)

Published: Dec. 8, 2021

To achieve an ultimate wide color gamut for ultrahigh-definition displays, there is great demand the development of organic light-emitting diodes (OLEDs) enabling monochromatic, ultrapure blue electroluminescence (EL). Herein, high-efficiency and OLEDs based on polycyclo-heteraborin multi-resonance thermally activated delayed fluorescence (MR-TADF) materials, BOBO-Z, BOBS-Z, BSBS-Z, are reported. The key to design present luminophores exquisite combination interplay multiple boron, nitrogen, oxygen, sulfur heteroatoms embedded in a fused polycyclic π-system. Comprehensive photophysical computational investigations this family MR-TADF materials reveal that systematic implementation chalcogen (oxygen sulfur) atoms can finely modulate emission while maintaining narrow bandwidth, as well spin-flipping rates between excited singlet triplet states. Consequently, BSBS-Z demonstrate narrowband EL emission, with peaks at 445-463 nm full width half maxima 18-23 nm, leading Commission Internationale de l'Éclairage-y coordinates range 0.04-0.08. Particularly, incorporating sulfur-doped BOBS-Z notably high maximum external quantum efficiencies 26.9% 26.8%, respectively, small efficiency roll-offs achieved concurrently.

Language: Английский

Citations

222
Molecular design of thermally activated delayed fluorescent emitters for narrowband orange–red OLEDs boosted by a cyano-functionalization strategy DOI Creative Commons
Yang Liu, Xin Xiao,

You Ran

et al.

Chemical Science, Journal Year: 2021, Volume and Issue: 12(27), P. 9408 - 9412

Published: Jan. 1, 2021

The first example of narrowband orange–red MR-TADF emitters has been developed, which realizes a record-high EQE 33.7% in OLEDs.

Language: Английский

Citations

212
One-Shot Synthesis of Expanded Heterohelicene Exhibiting Narrowband Thermally Activated Delayed Fluorescence DOI
Susumu Oda,

Bungo Kawakami,

Yuki Yamasaki

et al.

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 144(1), P. 106 - 112

Published: Dec. 23, 2021

An expanded heterohelicene consisting of three BN2-embedded [4]helicene subunits (V-DABNA-Mes) has been synthesized by one-shot triple borylation. The key to success is the excessive use boron tribromide in an autoclave. Based on multiple resonance effect and six nitrogen atoms, V-DABNA-Mes exhibited a narrowband sky-blue thermally activated delayed fluorescence with full width at half-maximum 16 nm. resonating π-extension minimized singlet-triplet energy gap enabled rapid reverse intersystem crossing rate constant 4.4 × 105 s-1. solution-processed organic light-emitting diode device, employed as emitter, emission 480 nm high external quantum efficiency 22.9%.

Language: Английский

Citations

205
Wide‐Range Color Tuning of Narrowband Emission in Multi‐resonance Organoboron Delayed Fluorescence Materials through Rational Imine/Amine Functionalization DOI

Minlang Yang,

So Shikita,

Hyukgi Min

et al.

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(43), P. 23142 - 23147

Published: Aug. 18, 2021

Abstract Establishing a simple and versatile design strategy to finely modulate emission colors while retaining high luminescence efficiency color purity remains an appealing yet challenging task for the development of multi‐resonance‐induced thermally activated delayed fluorescence (MR‐TADF) materials. Herein, we demonstrate that strategic introduction electron‐withdrawing imine electron‐donating amine moieties into boron‐embedded 1,3‐bis(carbazol‐9‐yl)benzene skeleton enables systematic hypsochromic bathochromic shifts narrowband emissions, respectively. By this method, effective electroluminescence tuning was accomplished over wide visible range from deep‐blue yellow (461–571 nm), using same MR molecular system, without compromising very narrow spectral features. Deep‐blue organic light‐emitting diodes with maximum external quantum efficiencies as 19.0–29.2 % superb could be produced family color‐tunable MR‐TADF emitters.

Language: Английский

Citations

203
Hypsochromic Shift of Multiple‐Resonance‐Induced Thermally Activated Delayed Fluorescence by Oxygen Atom Incorporation DOI
Hiroyuki Tanaka, Susumu Oda, Gaetano Ricci

et al.

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(33), P. 17910 - 17914

Published: May 26, 2021

Abstract Herein, we reported an ultrapure blue multiple‐resonance‐induced thermally activated delayed fluorescence (MR‐TADF) material ( ν‐DABNA‐O‐Me ) with a high photoluminescence quantum yield and large rate constant for reverse intersystem crossing. Because of restricted π‐conjugation the HOMO rather than LUMO induced by oxygen atom incorporation, shows hypsochromic shift compared to parent MR‐TADF ν‐DABNA ). An organic light‐emitting diode based on this exhibits emission at 465 nm, small full‐width half‐maximum 23 nm Commission Internationale de l'Eclairage coordinates (0.13, 0.10), maximum external efficiency 29.5 %. Moreover, facilitates drastically improved roll‐off device lifetime , which demonstrates significant potential incorporation strategy.

Language: Английский

Citations

200