title: Understanding the Fluorescence of TADF Light-Emitting Dyes.
abstract: In order to afford in a controlled fashion fine-tuning of the color and the intensity of the emitted light of potential fluorophores for organic light-emitting diodes (OLED), directed molecular design based on a donor-spacer-acceptor model is undertaken. One way of increasing emission efficiency is triplet harvesting. This can be achieved by thermally activated delayed fluorescence (TADF) when triplet and singlet excited states are quasi degenerate. Molecular building units are selected and bound in a specific pattern to allow for increase in emission performance, also due to TADF. Using time-dependent density functional theory, the relevant singlet-singlet and triplet-singlet energy gaps corresponding to absorption or emission transitions of the compounds are computed to simulate the electroluminescent spectrum. The results are analyzed in depth and relations between some spectral and structural properties are proposed. The best suited molecules are delineated as potential OLED building blocks. Guidelines for systematic improvement of the molecular characteristics are outlined.
authors.affiliation: Department of Physical Chemistry, Faculty of Chemistry and Pharmacy, University of Sofia , 1 James Bourchier Avenue, 1164 Sofia, Bulgaria.
authors.forename: Georgi
authors.initials: G
authors.lastname: Valchanov
authors.affiliation: Department of Physical Chemistry, Faculty of Chemistry and Pharmacy, University of Sofia , 1 James Bourchier Avenue, 1164 Sofia, Bulgaria.
authors.forename: Anela
authors.initials: A
authors.lastname: Ivanova
authors.affiliation: Department of Physical Chemistry, Faculty of Chemistry and Pharmacy, University of Sofia , 1 James Bourchier Avenue, 1164 Sofia, Bulgaria.
authors.forename: Alia
authors.initials: A
authors.lastname: Tadjer
authors.affiliation: Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Dennis
authors.initials: D
authors.lastname: Chercka
authors.affiliation: Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Baumgarten