Thermally Activated Delayed Fluorescence Materials Based on Carbazole/Sulfone

2014 ◽  
Vol 1044-1045 ◽  
pp. 158-163
Author(s):  
Bin Huang ◽  
Wei Jiang ◽  
Yuan Yuan Liu ◽  
Ya An Zhang ◽  
Ya Ping Yang ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Properties ◽  
Energy Gap ◽  
Theoretical Calculations ◽  
Suzuki Coupling ◽  
Delayed Fluorescence ◽  
Coupling Reactions ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Diphenyl Sulfone

A series of bipolar materials for thermally activated delayed fluorescence (TADF) based on carbazole and diphenylsulfone, is synthesized by Ulmann and Suzuki coupling reactions. In these materials, the 3,6-di-tert-butylcarbazole and N-phenylcarbazole group as donors are linked at the 3-, 4-position of diphenyl sulfone. The electronic, photophysical and electrochemical properties of these materials are studied by extensive UV-vis, fluorescence spectroscopic measurements, cyclic voltammetry as well as theoretical calculations. The energy gap between singlet and triplet (△EST) in these materials is tuned from 0.99 eV to 0.24 eV by changing the donor units and the positions of substitution.

Ni-catalyzed cascade coupling reactions: synthesis and thermally-activated delayed fluorescence characterization of quinazolinone derivatives

2021 ◽  
Author(s):  
Zhongyan Chen ◽  
Lepeng Chen ◽  
Shou-Feng Zhang ◽  
Qianqian Zhen ◽  
Wenzhang Xiong ◽  
...  
Keyword(s):  
Functional Groups ◽  
Room Temperature ◽  
Delayed Fluorescence ◽  
Coupling Reactions ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Quinazolinone Derivatives

A nickel-catalyzed synthesis of 1,3-diaryl-6H-pyrazino[2,1-b]quinazolin-6-one was developed. This method enabled to access valuable pyrazino-fused quinazolinones with tolerance of many functional groups even at room temperature. The desired pyrazino-fused quinazolinones emit...

Study of an Oxadiazole Derivative for a Blue Thermally Activated Delayed Fluorescence Emitter

2015 ◽  
Vol 15 (10) ◽  
pp. 7828-7831 ◽  
Author(s):  
Dong Yuel Kwon ◽  
Geon Hyeong Lee ◽  
Young Sik Kim
Keyword(s):  
Excited States ◽  
Energy Gap ◽  
Delayed Fluorescence ◽  
Excited Singlet ◽  
Thermally Activated Delayed Fluorescence ◽  
Excited Triplet ◽  
Thermally Activated ◽  
Donor And Acceptor ◽  
Homo And Lumo ◽  
Dft And Tddft Calculations

Novel thermally activated delayed fluorescence (TADF) materials (ACR-OXD, 2ACR-OXD) with 9,10- dihydro-9,9-dimethylacridine (ACR) as an electron donor and oxadiazole derivative (OXD) as an electron acceptor were designed and theoretically investigated for blue OLED emitter. Using DFT and TDDFT calculations, we gained the electron distribution of HOMO and LUMO and the energy of the lowest singlet (S1) and the lowest triplet (T1) excited states. In comparison with the previously reported a xanthen derivative (ACR-XTN), ACR-OXD exhibits a promising blue TADF emitter because of destabilizing the LUMO of ACR-OXD by the change of the electron accepting group and maintaining the steric hindrance between donor and acceptor moieties which lead to efficient TADF due to the small energy gap between the lowest excited singlet (S1) state and the lowest excited triplet (T1) state.

scholarly journals A Novel Design Strategy for Suppressing Efficiency Roll-Off of Blue Thermally Activated Delayed Fluorescence Molecules through Donor–Acceptor Interlocking by C–C Bonds

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1735 ◽  
Author(s):  
Tae Hui Kwon ◽  
Soon Ok Jeon ◽  
Masaki Numata ◽  
Hasup Lee ◽  
Yeon Sook Chung ◽  
...  
Keyword(s):  
Energy Gap ◽  
Delayed Fluorescence ◽  
Triplet Energy ◽  
Design Synthesis ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Display Performance ◽  
Commercial Applications

The short material lifetime of thermally activated delayed fluorescence (TADF) technology is a major obstacle to the development of economically feasible, highly efficient, and durable devices for commercial applications. TADF devices are also hampered by insufficient operational stability. In this paper, we report the design, synthesis, and evaluation of new TADF molecules possessing a sterically twisted skeleton by interlocking donor and acceptor moieties through a C–C bond. Compared to C–N-bond TADF molecules, such as CPT2, the C–C-bond TADF molecules showed a large dihedral angle increase by more than 30 times and a singlet–triplet energy-gap decrease to less than 0.22 eV because of the steric hindrance caused by the direct C–C bond connection. With the introduction of a dibenzofuran core structure, devices comprising BMK-T317 and BMK-T318 exhibited a magnificent display performance, especially their external quantum efficiencies, which were as high as 19.9% and 18.8%, respectively. Moreover, the efficiency roll-off of BMK-T318 improved significantly (26.7%). These results indicate that stability of the material can be expected through the reduction of their singlet–triplet splitting and the precise adjustment of dihedral angles between the donor–acceptor skeletons.

Theoretical tuning of the singlet–triplet energy gap to achieve efficient long-wavelength thermally activated delayed fluorescence emitters: the impact of substituents

2017 ◽  
Vol 19 (32) ◽  
pp. 21639-21647 ◽  
Author(s):  
Lijuan Wang ◽  
Tao Li ◽  
Peicheng Feng ◽  
Yan Song
Keyword(s):  
Energy Gap ◽  
Delayed Fluorescence ◽  
Triplet Energy ◽  
Thermally Activated Delayed Fluorescence ◽  
Long Wavelength ◽  
Thermally Activated ◽  
The Impact ◽  
Electron Withdrawing Substituents

Long-wavelength TADF emitters could be achieved with both small ΔEST and high kr through introducing small electron-withdrawing substituents!

A blue thermally activated delayed fluorescence emitter developed by appending a fluorene moiety to a carbazole donor with meta-linkage for high-efficiency OLEDs

2018 ◽  
Vol 2 (5) ◽  
pp. 917-922 ◽  
Author(s):  
Jiao-Jiao Liang ◽  
Yun Li ◽  
Yi Yuan ◽  
Si-Hua Li ◽  
Xiang-Dong Zhu ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
High Efficiency ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated

A new TADF emitter was developed for blue OLEDs, and its thermal, photophysical and electrochemical properties were investigated.

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