Design of a Novel Selenium‐Containing Spiro Donor for Narrowband Blue Thermally Activated Delayed Fluorescence Emitters in OLEDs DOI Open Access
Mengke Li, RongLin Li, Zhizhi Li

et al.

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

Published: Dec. 26, 2024

Abstract Achieving high‐efficiency and narrowband deep‐blue emission is of great significance for organic light‐emitting diodes (OLEDs). Herein, a novel selenium‐containing spiro‐acridine donor, DspiroSe, designed constructing highly efficient blue emitters. The spiro structure DspiroSe contributes to suppressed aggregation‐caused quenching, while the selenium atom provides heavy‐atom effect. By attaching multiple resonance skeleton with different linkage strategies, two isomeric emitters sSeDDBN PsSe‐DABNA are obtained, which show promise as candidates OLEDs. Note that methods enable tuning spectrum from sky‐blue deep‐blue, demonstrating exceptional characterized by full‐width at half‐maximum 18 nm peak wavelength 445 in solution. Both exhibit high photoluminescence quantum yields exceeding 90% films, OLEDs using them achieve maximum external efficiencies (EQE max ) 26.5% 14.6%, respectively. utilizing TADF assistant host, EQE further increases 28.5% 19.1% PsSe‐DABNA. Notably, based excellent color purity Commission Internationale de l'Eclairage coordinates (0.145, 0.052), closely approaching BT.2020 standard.

Language: Английский

Synergetic Multiple Charge‐Transfer Excited States for Anti‐Quenching and Rapid Spin‐Flip Multi‐Resonance Thermally Activated Delayed Fluorescence Emitter DOI Open Access

Lixiao Guo,

Weibo Cui,

Linjie Li

et al.

Advanced Materials, Journal Year: 2025, Volume and Issue: unknown

Published: March 29, 2025

The development of multiple resonances thermally activated delayed fluorescence (MR-TADF) emitters exhibiting high efficiency, narrowband emission, rapid reverse intersystem crossing rate (kRISC), and suppressed concentration quenching simultaneously is great significance yet a formidable challenge. Herein, an effective strategy presented to realize the above target by synergizing charge-transfer excited states, including short-range charge transfer (SRCT), through-bond (TBCT), through-space (TSCT). proof-of-concept emitter 4tCz2B exhibits bright green emission with narrow full width at half maximum (FWHM) 21 nm (0.10 eV) in solution, photoluminescence quantum yield 97%, fast kRISC 7.8 × 105 s-1 significantly film state. As result, sensitizer-free organic light-emitting diodes (OLEDs) achieve external efficiencies (EQEmaxS) over 34.5% together unaltered peak 508 FWHM 26 doping concentrations ranging from 3 20 wt.%. Even ratio 50 wt.%, EQEmax still as 25.5%. More importantly, non-sensitized devices exhibit reduced efficiency roll-offs, minimum value 13.4% brightness 1000 cd m-2.

Language: Английский

Citations

0
Engineering Nitrogen/Carbonyl MR‐TADF Emitters: Spiro‐Lock and Tert‐Butyl Synergy in Narrowband Blue Emission DOI
Hongyan Yan, Dong‐Ying Zhou,

Shi‐Jie Ge

et al.

Small, Journal Year: 2025, Volume and Issue: unknown

Published: March 30, 2025

Abstract Multi‐resonance thermally activated delayed fluorescence (MR‐TADF) emitters with rigid planar structures are promising for their exceptional color purity and outstanding device efficiency. However, as an important MR unit, rigidly interlocked nitrogen/carbonyl‐based blue materials often face challenges like spectral broadening, red‐shifting, reduced efficiency compared to nitrogen/boron system. Herein, a peripheral modification strategy incorporating tert ‐butyl groups via spiro‐lock framework is used synthesize four molecules: QAO‐TF, TQAO‐TF, TQAO‐F, TSOQ. The structure solidifies the molecular framework, narrows emission bandwidth, elevates photoluminescence quantum yield over 96%. Meanwhile, introduce steric hindrance, isolating luminescent core suppressing intermolecular interactions in solid state, thereby improving while maintaining narrowband emission. Notably, TQAO‐F shows electroluminescence peak at 476 nm 25 full width half maximum (FWHM) external (EQE) of 31.7%. TSOQ, its oxygen‐induced charge effect, achieves pure FWHM 20 nm, surpassing 30% EQE without sensitizers. This overall performance suggests potential rival classic

Language: Английский

Citations

0
Comprehensive Review on the Structural Diversity and Versatility of Multi-Resonance Fluorescence Emitters: Advance, Challenges, and Prospects toward OLEDs DOI Creative Commons
Xiugang Wu,

Songqian Ni,

Chih‐Hsing Wang

et al.

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

Published: May 9, 2025

Fluorescence emitters with a multiple-resonant (MR) effect have become research hotspot. These MR mainly consist of polycyclic aromatic hydrocarbons boron/nitrogen, nitrogen/carbonyl, and indolocarbazole frameworks. The staggered arrangement the highest occupied molecular orbital lowest unoccupied facilitates MR, resulting in smaller internal reorganization energy narrower emission bandwidth. Optimal charge separation suppresses gap between singlet triplet excited states, favoring thermally activated delayed fluorescence (TADF). MR-TADF materials, due to color purity high efficiency, are excellent candidates for organic light-emitting diodes. Nevertheless, significant challenges remain; particular, limitation imposed by alternated core configuration hinders their diversity versatility. Most existing materials concentrated blue-green range, only few red near-infrared spectra. This review provides timely comprehensive screening from pioneering work present. Our goal is gain understandings structure-performance relationship both basic advanced perspectives. Special emphasis placed on exploring correlations chemical structure, photophysical properties electroluminescent performance depth breadth an aim promote future development emitters.

Language: Английский

Citations

0
Tuning strength of Donor-Acceptor Unit: Enabling transition between Through-Bond and Through-Space charge transfer in HLCT emissions DOI
Yu Li, Ziyu Zhang, Fengwei Gao

et al.

Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy, Journal Year: 2025, Volume and Issue: 343, P. 126509 - 126509

Published: June 1, 2025

Language: Английский

Citations

0
Highly Efficient Green Multi‐Resonance Thermally Activated Delayed Fluorescence Emitters with Suppression of Concentration Quenching DOI Open Access

Liang Wan,

Zhuang Cheng,

Xiaobo Ma

et al.

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

Published: Dec. 16, 2024

Abstract High‐efficiency multi‐resonance thermally activated delayed fluorescence (MR‐TADF) emitters with narrowband emission show great potential for organic light‐emitting diodes (OLEDs). However, their inherent planar rigid structures often lead to intractable challenges of spectral broadening, self‐quenching, and low device efficiency at high dopant concentrations. Herein, two steric isomers, BN‐1TPh BN‐2TPh, are designed by incorporating bulky shielding unit (1,3,5‐triphenylbenzene) the para‐ position B atom in MR skeleton hinder intermolecular interactions. They both enhanced photoluminescence quantum yields (PLQYs) as compared model compound BCzBN. The corresponding OLEDs based on BN‐2TPh display maximum external (EQE max ) values up 30.8% 30.4% narrow full width half (FWHM) bands 27 28 nm, respectively. It is worth noting that even doping ratio 20%, EQEs still maintained 24.8% 25.7% almost unchanged spectra. These results segregating MR‐TADF spatial structure can weaken interaction, which one effective ways resist aggregation‐caused quenching effect achieve high‐efficiency concentration‐indispensible OLEDs.

Language: Английский

Citations

1
Design of a Novel Selenium‐Containing Spiro Donor for Narrowband Blue Thermally Activated Delayed Fluorescence Emitters in OLEDs DOI Open Access
Mengke Li, RongLin Li, Zhizhi Li

et al.

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

Published: Dec. 26, 2024

Abstract Achieving high‐efficiency and narrowband deep‐blue emission is of great significance for organic light‐emitting diodes (OLEDs). Herein, a novel selenium‐containing spiro‐acridine donor, DspiroSe, designed constructing highly efficient blue emitters. The spiro structure DspiroSe contributes to suppressed aggregation‐caused quenching, while the selenium atom provides heavy‐atom effect. By attaching multiple resonance skeleton with different linkage strategies, two isomeric emitters sSeDDBN PsSe‐DABNA are obtained, which show promise as candidates OLEDs. Note that methods enable tuning spectrum from sky‐blue deep‐blue, demonstrating exceptional characterized by full‐width at half‐maximum 18 nm peak wavelength 445 in solution. Both exhibit high photoluminescence quantum yields exceeding 90% films, OLEDs using them achieve maximum external efficiencies (EQE max ) 26.5% 14.6%, respectively. utilizing TADF assistant host, EQE further increases 28.5% 19.1% PsSe‐DABNA. Notably, based excellent color purity Commission Internationale de l'Eclairage coordinates (0.145, 0.052), closely approaching BT.2020 standard.

Language: Английский

Citations

1