Face-to-face order-packed mode promotes thermally activated delayed fluorescence to achieve stronger aggregation-induced emission

Wu, Xiulan; Gong, Cheng-Bin; Jiang, Xin; Gao, Jingran; Li, Ming; He, Rongxing; Chen, Ping; Shen, Wei

doi:10.1016/j.jsamd.2022.100432

Cited by 5 publications

(4 citation statements)

References 43 publications

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“…In addition, to synthesize the rigid orange-red TADF emitters, regulating their packing modes is another effective method of preparing high-efficiency orange-red light-emitting molecules. Typically, the intermolecular hydrogen bonds are usually designed to control donor-acceptor configurations for reducing nonradiative transition 5 , 22 , 32 , 33 . For example, ref.…”

Section: Introductionmentioning

confidence: 99%

Constructing high-efficiency orange-red thermally activated delayed fluorescence emitters by three-dimension molecular engineering

Hua

Liu

et al. 2022

Nat Commun

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Preparing high-efficiency solution-processable orange-red thermally activated delayed fluorescence (TADF) emitters remains challenging. Herein, we design a series of emitters consisting of trinaphtho[3,3,3]propellane (TNP) core derivatized with different TADF units. Benefiting from the unique hexagonal stacking architecture of TNPs, TADF units are thus kept in the cavities between two TNPs, which decrease concentration quenching and annihilation of long-lived triplet excitons. According to the molecular engineering of TADF and host units, the excited states can further be regulated to effectively enhance spin-orbit coupling (SOC) processes. We observe a high-efficiency orange-red emission at 604 nm in one instance with high SOC value of 0.862 cm−1 and high photoluminescence quantum yield of 70.9%. Solution-processable organic light-emitting diodes exhibit a maximum external quantum efficiency of 24.74%. This study provides a universal strategy for designing high-performance TADF emitters through molecular packing and excited state regulation.

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Section: Introductionmentioning

confidence: 99%

Constructing high-efficiency orange-red thermally activated delayed fluorescence emitters by three-dimension molecular engineering

Hua

Liu

et al. 2022

Nat Commun

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“…Until now, numerous research groups have documented successful instances of combining notable TADF and AIE properties. − To gain a deep understanding of the working mechanism of AIE-TADF, it is essential to comprehend the structural disparities between typical AIE-TADF and TADF compounds. Utilizing density functional theory methods, a series of structurally identical luminogens (Figure ) featuring a donor–acceptor framework have been studied.…”

Section: Introductionmentioning

confidence: 99%

Uncovering the Aggregation-Induced Emission Mechanisms of Phenoxazine and Phenothiazine Groups

Lin,

Gao,

et al. 2024

ACS Omega

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Molecules with both aggregation-induced emission (AIE) and thermally activated delayed fluorescence (TADF) properties are potential organic light-emitting diode materials; however, the AIE and TADF mechanisms are still debatable. In this work, four molecules incorporating carbazole (Cz), phenoxazine (PXZ), and phenothiazine (PTZ) as donor groups to the diphenylsulfone acceptor were investigated. The experiment results indicate that a molecule containing Cz exhibits solely TADF properties, whereas molecules containing PXZ and PTZ demonstrate both TADF and AIE characteristics. As for DPS-PTZ, the result indicates that the thin-film environment restricts molecular twisting, consequently reducing nonradiative decay, thereby attributing to the AIE property by density functional theory and molecular dynamics simulation. As for DPS-PXZ, the result suggests that the restricted access to a conical intersection in a singlet excited via an expansion in the C−S−C angle is the pivotal factor for the AIE characteristic. The C−S−C angle twist of DPS-PXZ is impeded in the aggregate state and resulted in luminescence. Understanding the mechanisms serves as a valuable guide for the development of new AIE systems, enabling their application in various practical domains.

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“…PH materials utilize triplet excitons by enhanced spin–orbital coupling between the lowest triplet excited state (T 1 ) and the ground state (S 0 ) with the help of the poisonous metals, ,, which are pollutants. Unlike PH materials, TADF materials successfully solve this problem via reverse intersystem crossing from T 1 to the lowest singlet excited state (S 1 ) under the thermal activation to make triplet excitons utilized efficiently. ,− So, TADF materials have been regarded as more promising materials for OLEDs after Adachi synthesized them, and TADF materials have been reported extensively in recent years. − Generally speaking, it is a consensus that TADF emitters are often co-doped with host materials − in most OLED devices to reduce triplet–triplet annihilation , and suppress concentration quenching . The host materials are beneficial in dispersing TADF molecules to improve the performance of devices.…”

Section: Introductionmentioning

confidence: 99%

Roles of Molecular Spatial Arrangement in Exciton Energy Transfer in Organic Light-Emitting Diodes: A Theoretical Study

et al. 2023

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Revealing the mechanism of exciton energy transfer (EET) in the emitting layer (EML) of organic light-emitting devices is significant for improving the device performance. In this paper, we explore how the host-TADF combinations influence EET in the amorphous film, especially for the Dexter energy transfer (DET) process. With the help of density functional theory calculations and molecular dynamics simulations, we study the Förster resonance energy transfer and the DET of two thin films (2,6-2CzBN:4tCzBN and 3,5-2CzBN:4tCzBN) to determine how the intermolecular interaction influences the energy transfer. We find that the exciton coupling value is the decisive factor that leads to the external quantum efficiency difference between the two amorphous films by analyzing the variable in Marcus theory. The molecular spatial arrangement in 3,5-2CzBN is beneficial to enhance exciton coupling. The more space around benzonitriles helps to strengthen fragment interaction between benzonitriles, which plays a vital role in exciton coupling and spatial distribution. This work reveals how the molecular spatial arrangement and interaction influence energy transfer.

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Face-to-face order-packed mode promotes thermally activated delayed fluorescence to achieve stronger aggregation-induced emission

Cited by 5 publications

References 43 publications

Constructing high-efficiency orange-red thermally activated delayed fluorescence emitters by three-dimension molecular engineering

Constructing high-efficiency orange-red thermally activated delayed fluorescence emitters by three-dimension molecular engineering

Uncovering the Aggregation-Induced Emission Mechanisms of Phenoxazine and Phenothiazine Groups

Roles of Molecular Spatial Arrangement in Exciton Energy Transfer in Organic Light-Emitting Diodes: A Theoretical Study

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