A Simple and Strong Electron-Deficient 5,6-Dicyano[2,1,3]benzothiadiazole-Cored Donor-Acceptor-Donor Compound for Efficient Near Infrared Thermally Activated Delayed Fluorescence

Jakkapan Kumsampao; Chaiyon Chaiwai; Pongsakorn Chasing; Thanyarat Chawanpunyawat; Supawadee Namuangruk; Taweesak Sudyoadsuk; Vinich Promarak

doi:10.1002/asia.202000727

A Simple and Strong Electron-Deficient 5,6-Dicyano[2,1,3]benzothiadiazole-Cored Donor-Acceptor-Donor Compound for Efficient Near Infrared Thermally Activated Delayed Fluorescence

Chem Asian J. 2020 Oct 1;15(19):3029-3036. doi: 10.1002/asia.202000727. Epub 2020 Aug 28.

Authors

Jakkapan Kumsampao¹, Chaiyon Chaiwai¹, Pongsakorn Chasing¹, Thanyarat Chawanpunyawat¹, Supawadee Namuangruk², Taweesak Sudyoadsuk¹, Vinich Promarak^{1

3}

Affiliations

¹ Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Rayong, 21210, Thailand.
² National Nanotechnology Center, National Science and Technology Development Agency, Pathumthani, 12120, Thailand.
³ Research Network of NANOTEC-VISTEC on Nanotechnology for Energy, Vidyasirimedhi Institute of Science and Technology, Rayong, 21210, Thailand.

PMID: 32748490
DOI: 10.1002/asia.202000727

Abstract

Despite the success of thermally activated delayed fluorescent (TADF) materials in steering the next generation of organic light-emitting diodes (OLEDs), effective near infrared (NIR) TADF emitters are still very rare. Here, we present a simple and extremely high electron-deficient compound, 5,6-dicyano[2,1,3]benzothiadiazole (CNBz), as a strong electron-accepting unit to develop a sufficiently strong donor-acceptor (D-A) interaction for NIR emission. End-capping with the electron-donating triphenylamine (TPA) unit created an effective D-A-D type system, giving rise to an efficient NIR TADF emissive molecule (λ_em =750 nm) with a very small ΔE_ST of 0.06 eV. The electroluminescent device using this NIR TADF emitter exhibited an excellent performance with a high maximum radiance of 10020 mW Sr^-1 m^-2 , a maximum EQE of 6.57% and a peak wavelength of 712 nm.

Keywords: 5,6-dicyano[2,1,3]benzothiadiazole; near infrared fluorophore; strong electron deficient; thermally activated delayed fluorescence.

Abstract

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