We use cookies to ensure that we give you the best experience on our website. By continuing to browse this repository, you give consent for essential cookies to be used. You can read more about our Privacy and Cookie Policy.

Durham Research Online
You are in:

Investigation of the mechanisms giving rise to TADF in exciplex states.

dos Santos, Paloma Lays and Dias, Fernando B. and Monkman, Andrew P. (2016) 'Investigation of the mechanisms giving rise to TADF in exciplex states.', Journal of physical chemistry C., 120 (32). pp. 18259-18267.


The donor–acceptor systems studied in this work have been demonstrated to show strong exciplex formation by their red-shifted PL emission when compared with the individual donor and acceptor molecules, and all give rise to delayed fluorescence. In all cases, the channels by which this delayed fluorescence is generated, along with the energy levels involved in reverse intersystem crossing (rISC), that is, which triplet levels the charge-transfer states couple to yield spin flip, have not previously been identified. Here the intermolecular charge transfer states formed in the donor–acceptor molecular pairs are studied. It is demonstrated that the local triplet excited states are the states that couple to the singlet charge-transfer excited state, defining the rISC process and hence thermally activated delayed fluorescence (TADF) mechanism. Moreover, in most systems there is a competition between delayed fluorescence mechanisms, triplet triplet annihilation and TADF, and this is analysed in detail. New design rules for exciplex materials showing dominant delayed fluorescence due to rISC for the device based on TADF are elucidated.

Item Type:Article
Full text:(AM) Accepted Manuscript
Download PDF
Publisher Web site:
Publisher statement:This document is the Accepted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see
Date accepted:19 July 2016
Date deposited:09 November 2016
Date of first online publication:26 July 2016
Date first made open access:26 July 2017

Save or Share this output

Look up in GoogleScholar