Thermally activated delayed fluorescence in dibenzothiophene sulfone derivatives: Theory and experiment

• Published in: Chemical physics letters Vol. 717; pp. 53 - 58
• Main Authors: Gadirov, R.M., Valiev, R.R., Samsonova, L.G., Degtyarenko, K.M., Izmailova, N.V., Odod, A.V., Krasnikova, S.S., Yakushchenko, I.K., Kopylova, T.N.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 16-02-2019
• Subjects: Intersystem crossing; Organic light emitting device; Spin-orbit coupling; Thermally activated delayed fluorescence; Transition electroluminescence; Thermally activated delayed fluorescence; Spin-orbit coupling; Intersystem crossing; Organic light emitting device; Transition electroluminescence
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2019.01.014

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•The photophysical properties of dyes are calculated.•The reversed intersystem crossing rate constant is obtained.•The OLEDs are fabricated.
The photophysical properties are calculated for the dibenzothiophene sulfone substituted with various electron donor moieties:3,7-bis[N,N-di(4-tert-butylphenyl)amino]dibenzothiophene-S,S-dioxide (1L), 2,8-bis[N,N-di(4-tert-butylphenyl)amino]dibenzothiophene-S,S-dioxide (1A), and 2,8-bis[N,N-di(4 methoxyphenyl)amino]dibenzothiophene-S,S-dioxide (2A). It is shown that the linear arrangement of the electron donor substituents relative to the dibenzothiophene sulfone acceptor turns compound (1L) an efficient prompt fluorescent emitter, while the angular arrangement of the substituents decreases the efficiency of prompt fluorescence, but increases the efficiency of thermally activated delayed fluorescence (TADF). Replacing the auxiliary tert-butyl groups in the donor moieties by methoxy groups leads to an increase in kISC and kRISC. OLEDs are made with the studied compounds.