A Thermally Activated Delayed Fluorescence Emitter Investigated by Time-Resolved Near-Infrared Spectroscopy

Wiebke Haselbach; Jeremy M Kaminski; Laura N Kloeters; Thomas J J Müller; Oliver Weingart; Christel M Marian; Peter Gilch; Barbara E Nogueira de Faria

doi:10.1002/chem.202202809

A Thermally Activated Delayed Fluorescence Emitter Investigated by Time-Resolved Near-Infrared Spectroscopy

Chemistry. 2023 Jan 9;29(2):e202202809. doi: 10.1002/chem.202202809. Epub 2022 Nov 17.

Authors

Wiebke Haselbach¹, Jeremy M Kaminski², Laura N Kloeters³, Thomas J J Müller³, Oliver Weingart², Christel M Marian², Peter Gilch¹, Barbara E Nogueira de Faria¹

Affiliations

¹ Institut für Physikalische Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany.
² Institut für Theoretische Chemie und Computerchemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany.
³ Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany.

Abstract

Emitters for organic light-emitting diodes (OLEDs) based on thermally activated delayed fluorescence (TADF) require small singlet (S₁ )-triplet (T₁ ) energy gaps as well as fast intersystem crossing (ISC) transitions. These transitions can be mediated by vibronic mixing with higher excited states S_n and T_n (n=2, 3, 4, …). For a prototypical TADF emitter consisting of a triarylamine and a dicyanobenzene moiety (TAA-DCN) it is shown that these higher states can be located energetically by time-resolved near-infrared (NIR) spectroscopy.

Keywords: NIR spectroscopy; UV/VIS spectroscopy; intersystem crossing; thermally activated delayed fluorescence; time-resolved spectroscopy.

Grants and funding

396890929/GRK 2482, "ModISC"/Deutsche Forschungsgemeinschaft