Skip to main content

Research Repository

Advanced Search

Persistent Dimer Emission in Thermally Activated Delayed Fluorescence Materials

Etherington, Marc K.; Kukhta, Nadzeya A.; Higginbotham, Heather F.; Danos, Andrew; Bismillah, Aisha N.; Graves, David R.; McGonigal, Paul R.; Haase, Nils; Morherr, Antonia; Batsanov, Andrei S.; Pflumm, Christof; Bhalla, Vandana; Bryce, Martin R.; Monkman, Andrew P.

Persistent Dimer Emission in Thermally Activated Delayed Fluorescence Materials Thumbnail


Marc K. Etherington

Nadzeya A. Kukhta

Heather F. Higginbotham

Aisha N. Bismillah

Nils Haase

Antonia Morherr

Christof Pflumm

Vandana Bhalla


We expose significant changes in emission color of carbazole-based thermally activated delayed fluorescence (TADF) emitters that arise through the presence of persistent dimer states in thin films and organic light-emitting diodes(OLEDs). Direct photoexcitation of this dimer state in 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN) reveals the significant influence of dimer species on the color purity of its photoluminescence and electroluminescence. The dimer species is sensitive to the sample preparation method and its enduring presence contributes to the widely reported concentration-mediated redshift in the photoluminescence and electroluminescence of evaporated thin films. This discovery has significant implications on the usability of these, and similar, molecules for OLEDs and explains disparate electroluminescence spectra presented in the literature for these compounds. The significant dimerization-controlled changes observed in the TADF process and photoluminescence efficiency mean that careful consideration of dimer states is imperative in the design of future TADF emitters and the interpretation of previously reported studies of carbazole-based TADF materials.


Etherington, M. K., Kukhta, N. A., Higginbotham, H. F., Danos, A., Bismillah, A. N., Graves, D. R., …Monkman, A. P. (2019). Persistent Dimer Emission in Thermally Activated Delayed Fluorescence Materials. Journal of Physical Chemistry C, 123(17), 11109-11117.

Journal Article Type Article
Acceptance Date Apr 3, 2019
Online Publication Date Apr 3, 2019
Publication Date May 2, 2019
Deposit Date Apr 3, 2019
Publicly Available Date May 2, 2019
Journal Journal of Physical Chemistry C
Print ISSN 1932-7447
Electronic ISSN 1932-7455
Publisher American Chemical Society
Peer Reviewed Peer Reviewed
Volume 123
Issue 17
Pages 11109-11117


Published Journal Article (Advance Online Version) (3.1 Mb)

Publisher Licence URL

Copyright Statement
Advance Online Version This is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited.

You might also like

Downloadable Citations