Highly efficient pure-blue organic light-emitting diodes based on rationally designed heterocyclic phenophosphazinine-containing emitters DOI Creative Commons
Yanping Huo,

Longjiang Xing,

Jianghui Wang

et al.

Research Square (Research Square), Journal Year: 2024, Volume and Issue: unknown

Published: Feb. 8, 2024

Abstract Multi-resonance thermally activated delayed fluorophores have been actively studied for high-resolution photonic applications due to their exceptional color purity. However, these compounds encounter challenges associated with the inefficient spin-flip process, compromising device performance. Herein, we designed and synthesized two pure-blue emitters based on an organoboron multi-resonance core, incorporating a conformationally flexible donor, 10-phenyl-5H-phenophosphazinine 10-oxide (or sulfide). This design concept selectively modifies orbital type of high-lying excited states charge transfer configuration while simultaneously providing necessary conformational freedom enhance density without sacrificing We show that different embedded phosphorus motifs (phosphine oxide/sulfide) donor can finely tune electronic structure freedom, resulting in accelerated process through intense spin-vibronic coupling, achieving over 27-fold increase reverse intersystem crossing rate compared parent emitter. Utilizing new emitters, achieved high-performance pure blue organic light-emitting diodes, showcasing top-tier external quantum efficiency 37.6% reduced roll-offs. proposed strategy not only conventional notion electron-donors are undesirable constructing narrowband but also offers pathway designing efficient narrow-spectrum diodes.

Language: Английский

Highly efficient pure-blue organic light-emitting diodes based on rationally designed heterocyclic phenophosphazinine-containing emitters DOI Creative Commons

Longjiang Xing,

Jianghui Wang, Wen‐Cheng Chen

et al.

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: July 22, 2024

Abstract Multi-resonance thermally activated delayed fluorophores have been actively studied for high-resolution photonic applications due to their exceptional color purity. However, these compounds encounter challenges associated with the inefficient spin-flip process, compromising device performance. Herein, we report two pure-blue emitters based on an organoboron multi-resonance core, incorporating a conformationally flexible donor, 10-phenyl-5 H -phenophosphazinine 10-oxide (or sulfide). This design concept selectively modifies orbital type of high-lying excited states charge transfer configuration while simultaneously providing necessary conformational freedom enhance density without sacrificing We show that different embedded phosphorus motifs (phosphine oxide/sulfide) donor can finely tune electronic structure and freedom, resulting in accelerated process through intense spin-vibronic coupling, achieving over 20-fold increase reverse intersystem crossing rate compared parent emitter. Utilizing emitters, achieve high-performance organic light-emitting diodes, showcasing top-tier external quantum efficiency 37.6% reduced roll-offs. proposed strategy not only conventional notion electron-donors are undesirable constructing narrowband but also offer pathway designing efficient narrow-spectrum blue diodes.

Language: Английский

Citations

26
B‒N covalent bond-involved π-extension of multiple resonance emitters enables high-performance narrowband electroluminescence DOI Creative Commons
Xingyu Huang, Jiahui Liu,

Yulin Xu

et al.

National Science Review, Journal Year: 2024, Volume and Issue: 11(6)

Published: March 23, 2024

ABSTRACT Multi-boron-embedded multiple resonance thermally activated delayed fluorescence (MR-TADF) emitters show promise for achieving both high color-purity emission and exciton utilization efficiency. However, their development is often impeded by a limited synthetic scope excessive molecular weights, which challenge material acquisition organic light-emitting diode (OLED) fabrication vacuum deposition. Herein, we put forward B‒N covalent bond-involved π-extension strategy via post-functionalization of MR frameworks, leading to the generation high-order B/N-based motifs. The structurally electronically extended π-system not only enhances rigidity narrow linewidth but also promotes reverse intersystem crossing mitigate efficiency roll-off. As illustrated examples, ultra-narrowband sky-blue (full-width at half-maximum as small 8 nm in n-hexane) have been developed with multi-dimensional improvement photophysical properties compared precursor emitters, enables narrowband OLEDs external quantum efficiencies (EQEmax) up 42.6%, company alleviated decline brightness, representing best reported single-host OLEDs. success these highlights effectiveness our design advanced MR-TADF confirms extensive potential high-performance optoelectronic devices.

Language: Английский

Citations

21
Sulfur-locked multiple resonance emitters for high performance orange-red/deep-red OLEDs DOI Creative Commons

Yexuan Pu,

Jin Qian, Yuewei Zhang

et al.

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Jan. 2, 2025

Language: Английский

Citations

2
Tailoring Ultra‐Narrowband Tetraborylated Multiple Resonance Emitter for High‐Performance Blue OLED DOI

Wenbo Yuan,

Jin Qian,

Mingxu Du

et al.

Advanced Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 10, 2024

Ultra-narrowband multiple resonance (MR) emitters are a key component in the fabrication of highly efficient and stable blue organic light-emitting diodes (OLEDs). To explore theoretical boundaries wavelength full width at half maximum (FWHM) emitters, currently narrowest boron-based MR emitter is carefully designed by integrating superior v-DABNA BBCz-DB structures under auspices ingenious short-range charge-transfer region regulation strategy. The target tetraboron compound TB-PB demonstrates emission with an 473 nm, small FWHM 12 nm CIEy coordinate 0.14. Benefiting from emitter's high photoluminescence quantum yield (99%), low excited-state energy (2.74 eV) short delayed fluorescence lifetime (0.53 µs), corresponding OLED achieves exceptional efficiencies 36.4%, 49.1 cd A

Language: Английский

Citations

8
Efficient OLEDs with Alleviated Efficiency Roll‐Off Based on MR‐TADF Materials Containing Indolo[3,2,1‐jk]carbazole DOI

Shi‐Quan Song,

Ching‐Fai Yip,

Qiming Liu

et al.

Advanced Optical Materials, Journal Year: 2024, Volume and Issue: 12(19)

Published: March 27, 2024

Abstract The multiple resonance thermally activated delayed fluorescence (MR‐TADF) materials can meet the requirement of a high color gamut displays due to their narrowband emission. However, most reported organic light‐emitting diodes (OLEDs) based on MR‐TADF suffer from severe efficiency roll‐off. Herein, three green emitters, p ‐ICz‐BNCz, m and dm are obtained by introducing bulky indolo[3,2,1‐ jk ]carbazole (ICz) units into classical DtBuCzB skeleton at para or meta positions relative boron‐substituted phenyl ring. Compared with ‐substitution ICz, not only increases reverse intersystem crossing rate constants ‐ICz‐BNCz nearly times, but also makes configurations more twisted. two factors work together improve utilization triplet excitons showing photoluminescence quantum yields exceeding 90%. As result, corresponding OLEDs exhibit maximum external (EQE max ) values 28% 32.9%, respectively, low‐efficiency At brightness 1000 cd −2 , EQE devices still maintain 19.3% 25.0%, respectively. In addition, emissions Commission Internationale de l'Eclairage coordinates (0.20, 0.70) (0.30, 0.67) observed.

Language: Английский

Citations

6
Efficient Deep‐Blue Organic Light‐Emitting Diodes Employing Doublet Sensitization DOI

Yufu Sun,

Xu‐Lin Chen, Donghai Zhang

et al.

Advanced Materials, Journal Year: 2024, Volume and Issue: 36(45)

Published: Sept. 10, 2024

Abstract Fast and efficient exciton utilization is a crucial solution highly desirable for achieving high‐performance blue organic light‐emitting diodes (OLEDs). However, the rate efficiency of in traditional OLEDs, which employ fully closed‐shell materials as emitters, are inevitably limited by spin statistical limitations transition prohibition. Herein, new sensitization strategy, namely doublet‐sensitized fluorescence (DSF), proposed to realize deep‐blue electroluminescence. In DSF‐OLED, doublet‐emitting cerium(III) complex, Ce‐2, utilized sensitizer multi‐resonance thermally activated delayed emitter ν ‐DABNA. Experimental results reveal that holes electrons predominantly recombine on Ce‐2 form doublet excitons, subsequently transfer energy singlet state ‐DABNA via exceptionally fast (over 10 8 s −1 ) (≈100%) Förster resonance emission. Due circumvention spin‐flip DSF mechanism, near‐unit remarkably short residence time 1.36 µs achieved proof‐of‐concept achieves Commission Internationale de l'Eclairage coordinate (0.13, 0.14), high external quantum 30.0%, small roll‐off 14.7% at luminance 1000 cd m −2 . The device exhibits significantly improved operational stability compared with unsensitized reference device.

Language: Английский

Citations

5
Intramolecular charge transfer assisted multi-resonance thermally activated delayed fluorescence emitters for high-performance solution-processed narrowband OLEDs DOI Creative Commons
Zhi Yang, Shengyu Li,

Lei Hua

et al.

Chemical Science, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Multi-resonance thermally activated delayed fluorescence (MR-TADF) emitters have been actively employed in high-resolution solution-processed organic light emitting diodes (OLEDs) due to their excellent color purity. Nonetheless, they are always confronted with intrinsic slow spin flip of triplet excitons, impeding the electroluminescence properties, especially non-sensitized OLEDs. Herein, we constructed intramolecular charge transfer (ICT) assisted MR-TADF by grafting donor-acceptor-type moieties a meta- or para-substitution as pendant on an organoboron multi-resonance core. The newly designed not only maintain short range characteristics emissive states without sacrificing purity but accelerated flips facilitated ICT process at high-lying state also confirmed ultrafast spectroscopy and theoretical calculation, achieving over 10-fold increase reverse intersystem crossing rate compared unsubstituted counterpart emitters. In sensitizer-free OLEDs, cutting-edge external quantum efficiency 27.8% can be achieved together reduced roll-offs attractive full width half maximum 29 nm, representing breakthrough for based narrowband

Language: Английский

Citations

0
Organic Thermally Activated Delayed Fluorescence (TADF) Compound as The Photosensitizer in CO2 Photoreduction: Taking 4CzIPN as An Example DOI

Youting Fang,

Yilin Xue,

Duobin Chao

et al.

Asian Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: April 25, 2025

Abstract Over the past decades, excessive CO₂ emissions have caused severe environmental problems, primarily global warming and climate change. To address these challenges, researchers developed photocatalytic approaches to convert into high‐value‐added chemicals. The development of efficient, green, cost‐effective reduction systems represents a crucial step toward sustainable energy solutions. However, replacing noble metal‐based photosensitizers, which are widely used in reduction, with more alternatives remains challenging. Thermally activated delayed fluorescence (TADF) compounds emerged as promising organic offering high quantum efficiency, long lifetimes, wide redox window. Notably, 1,2,3,5‐Tetrakis(carbazol‐9‐yl)‐4,6‐dicyanobenzene (4CzIPN), prototypical TADF compound, has demonstrated exceptional performance various systems. This review systematically summarizes recent advances TADF‐based particularly 4CzIPN, for while elucidating their underlying reaction mechanisms.

Language: Английский

Citations

0
Overcrowded steric engineering of through-space interactions for anti-quenching multi-resonance TADF materials DOI
Ru‐Jia Wang,

Fan Zheng,

Jie Hu

et al.

Chemical Engineering Journal, Journal Year: 2025, Volume and Issue: unknown, P. 163327 - 163327

Published: May 1, 2025

Language: Английский

Citations

0
Spirobifluorene-fused strategy enables pure-green multiple resonance emitters with low efficiency roll-off DOI

Hu Cheng,

Jingbo Lan, Yudong Yang

et al.

Materials Horizons, Journal Year: 2024, Volume and Issue: 11(19), P. 4674 - 4680

Published: Jan. 1, 2024

The spiroannulation of multiple resonance core skeleton gives rise to pure-green emitters and superior electroluminescence performance with low efficiency roll-off.

Language: Английский

Citations

3