Cargando…

TDDFT versus GW/BSE Methods for Prediction of Light Absorption and Emission in a TADF Emitter

[Image: see text] Design concepts for organic light emitting diode (OLED) emitters, which exhibit thermally activated delayed fluorescence (TADF) and thereby achieve quantum yields exceeding 25%, depend on singlet–triplet splitting energies of order kT to allow reverse intersystem crossing at ambien...

Descripción completa

Detalles Bibliográficos
Autores principales: Chaudhuri, D., Patterson, C. H.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2022
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9806837/
https://www.ncbi.nlm.nih.gov/pubmed/36515973
http://dx.doi.org/10.1021/acs.jpca.2c06403
_version_ 1784862600150908928
author Chaudhuri, D.
Patterson, C. H.
author_facet Chaudhuri, D.
Patterson, C. H.
author_sort Chaudhuri, D.
collection PubMed
description [Image: see text] Design concepts for organic light emitting diode (OLED) emitters, which exhibit thermally activated delayed fluorescence (TADF) and thereby achieve quantum yields exceeding 25%, depend on singlet–triplet splitting energies of order kT to allow reverse intersystem crossing at ambient temperatures. Simulation methods for these systems must be able to treat relatively large organic molecules, as well as predict their excited state energies, transition energies, singlet–triplet splittings, and absorption and emission cross sections with reasonable accuracy, in order to prove useful in the design process. Here we compare predictions of TDDFT with M06-2X and ωB97X-D exchange-correlation functionals and a G(o)W(o)@HF/BSE method for these quantities in the well-studied DPTZ-DBTO2 TADF emitter molecule. Geometry optimization is performed for ground state (GS) and lowest donor–acceptor charge transfer (CT) state for each functional. Optical absorption and emission cross sections and energies are calculated at these geometries. Relaxation energies are on the order of 0.5 eV, and the importance of obtaining excited state equilibrium geometries in predicting delayed fluorescence is demonstrated. There are clear trends in predictions of G(o)W(o)@HF/BSE, and TDDFT/ωB97X-D and M06-2X methods in which the former method favors local exciton (LE) states while the latter favors DA CT states and ωB97X-D makes intermediate predictions. G(o)W(o)@HF/BSE suffers from triplet instability for LE states but not CT states relevant for TADF. Shifts in HOMO and LUMO levels on adding a conductor-like polarizable continuum model dielectric background are used to estimate changes in excitation energies on going from the gas phase to a solvated molecule.
format Online
Article
Text
id pubmed-9806837
institution National Center for Biotechnology Information
language English
publishDate 2022
publisher American Chemical Society
record_format MEDLINE/PubMed
spelling pubmed-98068372023-01-03 TDDFT versus GW/BSE Methods for Prediction of Light Absorption and Emission in a TADF Emitter Chaudhuri, D. Patterson, C. H. J Phys Chem A [Image: see text] Design concepts for organic light emitting diode (OLED) emitters, which exhibit thermally activated delayed fluorescence (TADF) and thereby achieve quantum yields exceeding 25%, depend on singlet–triplet splitting energies of order kT to allow reverse intersystem crossing at ambient temperatures. Simulation methods for these systems must be able to treat relatively large organic molecules, as well as predict their excited state energies, transition energies, singlet–triplet splittings, and absorption and emission cross sections with reasonable accuracy, in order to prove useful in the design process. Here we compare predictions of TDDFT with M06-2X and ωB97X-D exchange-correlation functionals and a G(o)W(o)@HF/BSE method for these quantities in the well-studied DPTZ-DBTO2 TADF emitter molecule. Geometry optimization is performed for ground state (GS) and lowest donor–acceptor charge transfer (CT) state for each functional. Optical absorption and emission cross sections and energies are calculated at these geometries. Relaxation energies are on the order of 0.5 eV, and the importance of obtaining excited state equilibrium geometries in predicting delayed fluorescence is demonstrated. There are clear trends in predictions of G(o)W(o)@HF/BSE, and TDDFT/ωB97X-D and M06-2X methods in which the former method favors local exciton (LE) states while the latter favors DA CT states and ωB97X-D makes intermediate predictions. G(o)W(o)@HF/BSE suffers from triplet instability for LE states but not CT states relevant for TADF. Shifts in HOMO and LUMO levels on adding a conductor-like polarizable continuum model dielectric background are used to estimate changes in excitation energies on going from the gas phase to a solvated molecule. American Chemical Society 2022-12-14 2022-12-29 /pmc/articles/PMC9806837/ /pubmed/36515973 http://dx.doi.org/10.1021/acs.jpca.2c06403 Text en © 2022 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by/4.0/Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Chaudhuri, D.
Patterson, C. H.
TDDFT versus GW/BSE Methods for Prediction of Light Absorption and Emission in a TADF Emitter
title TDDFT versus GW/BSE Methods for Prediction of Light Absorption and Emission in a TADF Emitter
title_full TDDFT versus GW/BSE Methods for Prediction of Light Absorption and Emission in a TADF Emitter
title_fullStr TDDFT versus GW/BSE Methods for Prediction of Light Absorption and Emission in a TADF Emitter
title_full_unstemmed TDDFT versus GW/BSE Methods for Prediction of Light Absorption and Emission in a TADF Emitter
title_short TDDFT versus GW/BSE Methods for Prediction of Light Absorption and Emission in a TADF Emitter
title_sort tddft versus gw/bse methods for prediction of light absorption and emission in a tadf emitter
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9806837/
https://www.ncbi.nlm.nih.gov/pubmed/36515973
http://dx.doi.org/10.1021/acs.jpca.2c06403
work_keys_str_mv AT chaudhurid tddftversusgwbsemethodsforpredictionoflightabsorptionandemissioninatadfemitter
AT pattersonch tddftversusgwbsemethodsforpredictionoflightabsorptionandemissioninatadfemitter