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

Multiple‐Resonance‐Induced Thermally Activated Delayed Fluorescence Materials Based on Indolo[3,2,1‐jk]carbazole with an Efficient Narrowband Pure‐Green Electroluminescence DOI

Xu‐Feng Luo,

Shi‐Quan Song,

Hua‐Xiu Ni

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(41)

Published: Aug. 19, 2022

Herein, we report two multiple-resonance thermally activated delayed fluorescence emitters (VTCzBN and TCz-VTCzBN) based on indolo[3,2,1-jk]carbazole unit boron-nitrogen skeletons, whose emissions peaking at 496 521 nm with full width half maximum of 34 29 nm, respectively. Meanwhile, fast rate constants reverse intersystem crossing above 106 s-1 are obtained due to small singlet-triplet energy gaps large spin-orbital coupling values. Notably, planar molecular structures along the transition dipole moment direction endow them high horizontal emitting ratios up 94 %. Consequently, corresponding organic light-emitting diodes (OLEDs) show external quantum efficiencies 31.7 % 32.2 %, Particularly, OLED TCz-VTCzBN display ultra-pure green emission Commission Internationale de l'Eclairage coordinates (0.22, 0.71), consistent standard National Television System Committee.

Language: Английский

Citations

119
Organoboron-based multiple-resonance emitters: synthesis, structure–property correlations, and prospects DOI Creative Commons
Masashi Mamada, Masahiro Hayakawa, Junki Ochi

et al.

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(3), P. 1624 - 1692

Published: Jan. 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.

Language: Английский

Citations

117
Solution‐Processable Pure‐Red Multiple Resonance‐induced Thermally Activated Delayed Fluorescence Emitter for Organic Light‐Emitting Diode with External Quantum Efficiency over 20 % DOI
Xinliang Cai, Yincai Xu, Yue Pan

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(7)

Published: Dec. 13, 2022

Abstract Developing solution‐processable red organic light‐emitting diodes (OLEDs) with high color purity and efficiency based on multiple resonance thermally activated delayed fluorescence (MR‐TADF) is a formidable challenge. Herein, by introducing auxiliary electron donor acceptor moieties into the highest occupied molecular orbital (HOMO) lowest unoccupied (LUMO) distributed positions of skeleton simultaneously, an effective strategy to obtain MR‐TADF emitters was represented. The proof‐of‐the‐concept molecule BN‐R exhibits narrowband pure‐red emission at 624 nm, luminous 94 % narrow bandwidth 46 nm. Notably, fabricated OLED state‐of‐the‐art external quantum over 20 Commission Internationale de I’Éclairage coordinates (0.663, 0.337) long operational lifetime (LT 50 ) 1088 hours initial luminance 1000 cd m −2 .

Language: Английский

Citations

113
Development of Pure Green Thermally Activated Delayed Fluorescence Material by Cyano Substitution DOI
Susumu Oda,

Takumi Sugitani,

Hiroyuki Tanaka

et al.

Advanced Materials, Journal Year: 2022, Volume and Issue: 34(32)

Published: June 21, 2022

Multiple resonance (MR)-effect-induced thermally activated delayed fluorescence (TADF) materials have garnered significant attention because they can achieve both high color purity and external quantum efficiency (EQE). However, the reported green-emitting MR-TADF exhibit broader emission compared to those of blue-emitting ones suffer from severe roll-off due insufficient rate constants reverse intersystem crossing process (kRISC ). Herein, a pure green material (ν-DABNA-CN-Me) with kRISC 105 s-1 is reported. The key success introduction cyano groups into (ν-DABNA), which causes remarkable bathochromic shift without loss purity. organic light-emitting diode employing it as an emitter exhibits at 504 nm small full-width half-maximum 23 nm, corresponding Commission Internationale d'Éclairage coordinates (0.13, 0.65). device achieves maximum EQE 31.9% successfully suppresses luminance.

Language: Английский

Citations

112
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

Citations

107