The Department of Theoretical Chemistry kindly invites to the following talk:

Prof. Daniel Escudero Masa; Department of Chemistry, KU Leuven, Belgium

"AB INITIO MODELLING OF PHOTOLUMINESCENCE"

In this contribution I present computational protocols to model photoluminescence in molecular systems which go beyond the nowadays routine modelling of emission energies. Our protocols merge state-of-the-art quantum chemical calculations, excited state decay rate theories (i.e., Fermi-golden rule based)[1] along with semi-classical nonadiabatic excited state dynamics to enable the quantitative determination of fluorescence lifetimes and quantum yields. In particular, I present an extensive analysis of the parameters influencing the excited state decay rate calculations.[2]  Further, protocols to model anti-Kasha fluorescence in molecular systems (i.e., fluorescence from higher-lying excited states)[3] and the first attempts to capturing fluorescence events in molecular systems within a semi-classical Non- Adiabatic Molecular Dynamics framework,[4] are presented. Finally, I present our recent efforts to expand our protocols from molecular systems to the solid state. In particular I present protocols allowing modeling the photophysical properties of organic molecular crystals. The objective is to evaluate the effect of various sources of disorder resulting in the broadening of UV-vis spectra.[5] These investigations contribute to our continuous efforts towards attaining quantitative determinations of photophysics and photochemistry at the first principles level.

Keywords

Quantum chemical investigations, excited state decay rates, photoluminescence

References

[1] Z. Shuai, Q. Peng, Phys. Rep., 537, 123 (2014).

[2] M. T. do Casal, K. Veys, M. H. E. Bousquet, D. Escudero, D. Jacquemin, J. Phys. Chem. A, 127, 10033 (2023); K. Veys, M. H. E. Bousquet, D. Jacquemin, D. Escudero, J. Chem. Theory and Comput., 19, 9344 (2023)

[3] K. Veys, D. Escudero, Acc. Chem. Res., 55, 2698 (2022).

[4] M. Pérez-Escribano, J. Jankowska, G. Granucci, D. Escudero, J. Chem. Phys., 158, 124104 (2023

[5] M. Hodée, D. Escudero, In preparation (2025)