Synergistic Modulation of Excited State Ingredients and Chiroptical Activity for High‐Performance Pure‐Green Circularly Polarized Electroluminescence DOI
Haoxin Huang, Nengquan Li, Wendi Li

et al.

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

Published: May 14, 2024

Abstract The integration of chiral elements within a multiple resonance (MR) motif affords prospective avenue to construct satisfying emitters tailored for state‐of‐the‐art circularly polarized organic light–emitting diodes (CP‐OLEDs). However, the concurrently realizing both high luminescence efficiency and favorable dissymmetry factors ( g PL ) still remains formidable challenge, particularly when aligning with requirement color purity. Herein, dual‐pronged approach is proposed reconcile such trade‐offs by directly fusing secondary donor onto MR scaffold, thereby facilitating hybrid short/long‐range charge‐transfer fine‐tuned compositions. Theoretical calculations unveil pronounced impact on meticulously refining characteristics excited states, therefore yielding considerable 3.3 × 10 −3 , along fluorescence quantum yield 0.97, rapid reverse intersystem crossing rate 3.06 5 s −1 in one embodiment. Leveraging these merits, electroluminescence devices incorporating them as dopants exhibit exceptional performance, showcasing peak external 36.6% remarkable Commission Internationale de L'Eclairage coordinates (0.19, 0.71), which represent most notable achievements among pure‐green CP‐OLEDs.

Language: Английский

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

Jibiao Jin,

Shumeng Wang, He Jiang

et al.

Advanced Optical Materials, Journal Year: 2024, Volume and Issue: 12(11)

Published: Feb. 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.

Language: Английский

Citations

13
Secondary donor-acceptor group enable efficient pure green organic light-emitting devices based on multi-resonance TADF emitters DOI

Xiangan Song,

Shaogang Shen,

Sheng‐Nan Zou

et al.

Chemical Engineering Journal, Journal Year: 2024, Volume and Issue: 481, P. 148794 - 148794

Published: Jan. 14, 2024

Language: Английский

Citations

12
Modulating electronic confinement and structural distortion of multiple resonance emitters enables high-performance ultrapure blue OLED DOI
Baoxi Li,

Jingli Lou,

B. Zhang

et al.

Chemical Engineering Journal, Journal Year: 2024, Volume and Issue: 482, P. 148876 - 148876

Published: Jan. 17, 2024

Language: Английский

Citations

10
Boron‐ and Oxygen‐Doped π‐Extended Helical Nanographene with Circularly Polarised Thermally Activated Delayed Fluorescence DOI
Geethu Venugopal, V. Ravi Kumar,

Ashok Badrinarayan Jadhav

et al.

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(19)

Published: Jan. 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.

Language: Английский

Citations

10
Structural Optimization of BODIPY Derivatives: Achieving Stable and Long-Lived Green Emission in Hyperfluorescent OLEDs DOI
Yogesh Gawale, Paramasivam Palanisamy,

Hyun Seung Lee

et al.

ACS Applied Materials & Interfaces, Journal Year: 2024, Volume and Issue: 16(17), P. 22274 - 22281

Published: April 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.

Language: Английский

Citations

9
Multi‐π‐Stacked Through‐Space Charge‐Transfer Emitters with Accelerated Radiative Decay for High‐Efficiency Organic Light‐Emitting Diodes with Suppressed Efficiency Roll‐Offs DOI Open Access
Yongjun Song, Ke Zhang, Yibo Li

et al.

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

Published: Jan. 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.

Language: Английский

Citations

1
Luminescent Organosilane and Organogermane MR‐TADF Emitters for Operationally Stable Blue Organic Light‐Emitting Diodes DOI Open Access
Sijie Li,

Xiongkai Tang,

Chiu Hwi Ng

et al.

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

Published: Jan. 10, 2025

Abstract Improving operational stability for organic light‐emitting diode (OLED) is a hotspot in scientific research. It proposed that silicon (Si) and germanium (Ge) can exhibit hyperconjugation effects participate conjugated systems, thereby stabilizing molecules’ excited polarized states. Herein, the importance of incorporating Si Ge multi‐resonance thermally activated delayed fluorescence emitters revealed to improve their luminescence efficiency intrinsic stability. Computational studies show introducing atoms strengthen C−Si C−Ge bonds due effect, resulting higher bond dissociation energies molecular photostability. With efficient spin‐vibronic coupling spin‐orbital coupling, flexible conformations facilitate spin‐flip processes by enriching characters density A maximum external quantum 30.0% BN ‐Ge ‐based blue‐emitting OLEDs, with (Commission Internationale de l'Eclairage) CIE y ≤ 0.18 realized. In particular, LT 90 at 1000 cd m −2 48.3 7.1 h achieved BN‐Si BN‐Ge respectively, using developed deuterated SiCzCz‐d 15 SiTriCz2‐d 16 as hole‐transporting host materials. anticipated study will provide insights into design group IV element‐containing multiple‐resonance fluorescent optoelectronics applications.

Language: Английский

Citations

1
Design high-performance narrowband emitters for blue light-emitting diodes through manipulating resonance structure of aromatic heterocycles DOI
Yue Yu, Lei Xu,

Wenle Tan

et al.

Science China Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 13, 2025

Language: Английский

Citations

1
Multiple Donor Modification of Boron‐Based Emitters to Produce Aggregation‐Induced Emission and Thermally Activated Delayed Fluorescence for Blue OLEDs DOI Open Access

Mohan Gandhi Devulapally,

Yeonju Jeong,

Jae Hee Lee

et al.

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

Published: Jan. 17, 2025

Abstract Two novel multi‐donor emitters, bearing 1,1,4,4,12,12,15,15‐octamethyl‐1,2,3,4,12,13,14,15‐octahydro‐6,10‐dioxa‐16 b ‐boraanthra[3,2,1‐ de ]tetracene (CyDOBNA) are presented. In 3TPA‐CyDOBNA, three electron‐rich triphenylamine (TPA) units positioned on the central benzene ring of CyDOBNA to maximize distortion from an acceptor plane. This modification reduces singlet–triplet energy gap (Δ E ST ) by 0.16 eV, highlighting its thermally activated delayed fluorescence (TADF) characteristics. However, congested TPA donors bottom side found facilitate non‐radiative decay in a triplet state, indicating that Δ alone is insufficient for optimal device performance. Further refinement led creation Ph2TPA‐CyDOBNA, where two and one phenyl group minimize pathways while preserving TADF behavior. results reverse intersystem crossing rate 2.30 × 10 5 s −1 0.15 eV. Photophysical investigations reveal these emitters exhibit not only but also aggregation‐induced emission properties, maintaining high photoluminescence quantum yield (PLQY) even solid state. doped OLED device, external efficiency (EQE) 18.9% achieved 3TPA‐CyDOBNA. Compared with EQE Ph2TPA‐CyDOBNA improves 21.1%, primarily because suppression excessive flexibility donors.

Language: Английский

Citations

1
Blue Multiple‐Resonance Thermally Activated Delayed Fluorescence Materials DOI Open Access
Boyao Cui, Jianqiao Zhou,

Chunbo Duan

et al.

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

Published: Feb. 8, 2025

Abstract Organic light‐emitting diodes (OLEDs) exhibit significant advantages in the fields of ultra‐high‐definition (UHD) displays and wearable devices. However, developing low‐cost, high‐efficiency, high‐purity blue emission materials remains a challenge for academia industry. While thermally activated delayed fluorescence (TADF) meet low‐cost manufacturing needs achieve 100% internal quantum efficiency, their charge‐transfer excited states lead to broad spectra that don't BT.2020 standard. Fortunately, multiple resonance (MR) strategy offers an effective solution creating TADF with high color purity. Through careful structural design precise tuning state energy levels, MR‐TADF can easily full‐width at half‐maximum (FWHM) less than 30 nm. Nevertheless, it still faces challenges, such as severe aggregation‐induced quenching efficiency roll‐off. Herein, this work overviews recent progress devices, introduce representative molecular strategies aimed suppressing concentration quenching, enhancing reverse intersystem crossing rates, achieving deep emission, which will aid future endeavors develop more efficient, stable devices suitable UHD display applications.

Language: Английский

Citations

1