Disclosing the Impact of Local Host Effects on TADF Dynamics

Fuente: arXiv
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Main Authors: Ewald, Björn, Kaiser, Theodor, Fleischmann, Thomas, Pflaum, Jens
Format: Preprint
Published: 2024
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author Ewald, Björn
Kaiser, Theodor
Fleischmann, Thomas
Pflaum, Jens
author_facet Ewald, Björn
Kaiser, Theodor
Fleischmann, Thomas
Pflaum, Jens
contents Donor-acceptor (D-A) type thermally activated delayed fluorescence (TADF), a key technology of proposed Gen3 organic light emitting diodes (OLEDs), is highly sensitive to the rigidity and polarity of the local environment. Specifically, the torsional flexibility of the D-A dihedral angle and the dipole character of charge transfer states give rise to a distribution of TADF dynamics across the emitter ensemble. Here, we employ single molecule spectroscopy to access the photophysics of individual emitters, thus overcoming the limitations of ensemble averaging. Using photon correlation measurements and locally resolved spectral data from single D-A type TADF molecules embedded in host materials of different polarity and rigidity, we derive host-dependent characteristics and distributions in the TADF dynamics. These are directly linked to local conformational freedom and dielectric properties, offering new insight into host-emitter interactions and enabling rational design strategies for optimized host-emitter combinations in OLED applications.
format Preprint
id arxiv_https___arxiv_org_abs_2406_15911
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Disclosing the Impact of Local Host Effects on TADF Dynamics
Ewald, Björn
Kaiser, Theodor
Fleischmann, Thomas
Pflaum, Jens
Applied Physics
Materials Science
Donor-acceptor (D-A) type thermally activated delayed fluorescence (TADF), a key technology of proposed Gen3 organic light emitting diodes (OLEDs), is highly sensitive to the rigidity and polarity of the local environment. Specifically, the torsional flexibility of the D-A dihedral angle and the dipole character of charge transfer states give rise to a distribution of TADF dynamics across the emitter ensemble. Here, we employ single molecule spectroscopy to access the photophysics of individual emitters, thus overcoming the limitations of ensemble averaging. Using photon correlation measurements and locally resolved spectral data from single D-A type TADF molecules embedded in host materials of different polarity and rigidity, we derive host-dependent characteristics and distributions in the TADF dynamics. These are directly linked to local conformational freedom and dielectric properties, offering new insight into host-emitter interactions and enabling rational design strategies for optimized host-emitter combinations in OLED applications.
title Disclosing the Impact of Local Host Effects on TADF Dynamics
topic Applied Physics
Materials Science
url https://arxiv.org/abs/2406.15911