Two-Channel Space Charge Transfer-Induced Thermally Activated Delayed Fluorescent Materials for Efficient OLEDs with Low Efficiency Roll-Off

2021 ◽  
Author(s):  
Ruifang Wang ◽  
Zhiyi Li ◽  
Taiping Hu ◽  
Lei Tian ◽  
Xiaoxiao Hu ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Space Charge ◽  
Thermally Activated ◽  
Fluorescent Materials ◽  
Low Efficiency ◽  
Channel Space

Fast Reverse Intersystem Crossing Over 107 s-1 in Organic Emitters with Inverted Singlet-Triplet Gap via Intramolecular Through Space Charge Transfer

2021 ◽  
Author(s):  
Yafei Wang ◽  
Xinrui Chen ◽  
Robert Pollice ◽  
Bing Li ◽  
Yuanyuan Zhu ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Space Charge ◽  
Intersystem Crossing ◽  
Acceptor Group ◽  
Fluorescent Materials ◽  
High Emission ◽  
Bond Charge ◽  
The Relationship ◽  
Donor Moiety ◽  
Insight Into

Controlling excited state properties to achieve fast reverse intersystem crossing rates of over 107 s-1 is still challenging for intramolecular through-space charge transfer (TSCT) based delayed fluorescent materials. To gain further insight into the relationship between through-space and through-bond charge transfer (TSCT/TBCT), herein, three compounds DPS-24Ac, DPS-25Ac and DPS-OAc were prepared and characterized via NMR, MS and single crystal, in which the diphenylsulfone (DPS) is used as the acceptor group and acridine (Ac) as the donor moiety. Intense emissions from blue to yellow with high emission efficiency of 70-100% are detected for all emitters. Both computations and experiments suggest that compounds DPS-24Ac and DPS-25Ac have a clear TSCT effect and also an inverted adiabatic singlet-triplet gap which can be explained by the kinetic exchange mechanism. Notably, compound DPS-24Ac achieves the highest reverse intersystem crossing rate constant (krISC) of over 107 s-1 via manipulation of both TSCT and TBCT effects. The solution-processed devices display maximum external quantum efficiencies of 21.73, 12.14 and 4.96% for DPS-24Ac, DPS-25Ac and DPS-OAc, respectively. Overall, this work provides a novel avenue to achieve highly-efficient OLED materials with fast rISC by controlling both TSCT and TBCT effects.

Blue Thermally Activated Delayed Fluorescence Polymers with Nonconjugated Backbone and Through-Space Charge Transfer Effect

2017 ◽  
Vol 139 (49) ◽  
pp. 17739-17742 ◽  
Author(s):  
Shiyang Shao ◽  
Jun Hu ◽  
Xingdong Wang ◽  
Lixiang Wang ◽  
Xiabin Jing ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Space Charge ◽  
Transfer Effect ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated

scholarly journals Through-space charge transfer hexaarylbenzene dendrimers with thermally activated delayed fluorescence and aggregation-induced emission for efficient solution-processed OLEDs

2019 ◽  
Vol 10 (10) ◽  
pp. 2915-2923 ◽  
Author(s):  
Xingdong Wang ◽  
Shumeng Wang ◽  
Jianhong Lv ◽  
Shiyang Shao ◽  
Lixiang Wang ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Space Charge ◽  
Efficient Solution ◽  
Delayed Fluorescence ◽  
Electron Donors ◽  
Solution Processed ◽  
Thermally Activated Delayed Fluorescence ◽  
Aggregation Induced Emission ◽  
Thermally Activated

Through-space charge transfer hexaarylbenzene dendrimers containing circularly-arrayed electron donors and acceptors exhibit thermally activated delayed fluorescence and aggregation-induced emission effects, giving EQE of 14.2% for solution-processed OLEDs.

Through-Space Charge Transfer Dendrimers Employing Oxygen-Bridged Triarylboron Acceptors for Efficient Deep-Blue Electroluminescence

2021 ◽  
Author(s):  
Baoyun Du ◽  
Xingdong Wang ◽  
Fan Chen ◽  
Qingqing Yang ◽  
Shiyang Shao ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Space Charge ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
State Of The Art ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Deep Blue

Though-space charge transfer dendrimers consisting of dendritic triacridan donors and oxygen-bridged triarylboron acceptors are demonstrated to exhibit deep-blue thermally activated delayed fluorescence with state-of-the-art external quantum efficiency of 14.6% for...

Circularly Polarized Thermally Activated Delayed Fluorescence Emitters in Through-Space Charge Transfer on Asymmetric Spiro Skeletons

2020 ◽  
Vol 142 (41) ◽  
pp. 17756-17765 ◽  
Author(s):  
Sheng-Yi Yang ◽  
Ya-Kun Wang ◽  
Chen-Chen Peng ◽  
Zheng-Guang Wu ◽  
Shuai Yuan ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Space Charge ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Circularly Polarized ◽  
Thermally Activated

scholarly journals Intramolecular Through-Space Charge-Transfer Emitters Featuring Thermally Activated Delayed Fluorescence for High-Efficiency Electroluminescent Devices

2021 ◽  
Author(s):  
Yongjun song ◽  
lei he ◽  
Mingxing Tian ◽  
Renyou Yu
Keyword(s):  
Charge Transfer ◽  
Space Charge ◽  
High Efficiency ◽  
Theoretical Calculations ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Thermally Activated ◽  
Donor Acceptor ◽  
First Time

Through-space charge-transfer (TSCT) emitters have been extensively explored for thermally activated delayed fluorescence (TADF), but arranging various donors and acceptors into rigid cofacial conformations for various efficient TSCT TADF emitters has still remained a challenge. Here we report for the first time a “fixing acceptor” design to reach various efficient TSCT TADF emitters. By chemically fixing the acceptor (benzophenone) with a rigid spiro structure and cofacially aligning various donors with the fixed acceptor, a series of efficient TSCT TADF emitters have been developed. Single-crystal structures and theoretical calculations have verified closely-packed cofacial donor/acceptor conformations and favorable TSCT in the emitters. The emitters afford sky-blue to yellow TADF emission in doped films, with high photoluminescent efficiencies of up to 0.92 and reverse intersystem crossing rates of up to 1.0×106 s−1. Organic light-emitting diodes using the emitters afford sky-blue to yellow electroluminescence with high external quantum efficiencies of up to 20.9%. The work opens a new avenue toward a wide variety of efficient TSCT TADF emitters.

Through Space Charge Transfer for Efficient Sky‐Blue Thermally Activated Delayed Fluorescence (TADF) Emitter with Unconjugated Connection

2019 ◽  
Vol 8 (2) ◽  
pp. 1901150 ◽  
Author(s):  
Ya‐Kun Wang ◽  
Chen‐Chao Huang ◽  
Hao Ye ◽  
Cheng Zhong ◽  
Aziz Khan ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Space Charge ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated
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