Osman Baris Malcioglu, Irene Bechis, Michel Bockstedte,
"Effect of crystallization on the electronic and optical properties of archetypal porphyrins"
, in PCCP - Physical Chemistry Chemical Physics, Vol. 20, Seite(n) 3825, 1-2020, ISSN: 1463-9076
Original Titel:
Effect of crystallization on the electronic and optical properties of archetypal porphyrins
Sprache des Titels:
Englisch
Original Kurzfassung:
Thin porphyrin films as employed in modern optical devices or photovoltaic applications show deviating
electronic and optical properties from the gasphase species. Any understanding of the physical origin
may pave way to a specific engineering of these properties via ligand or substituent control. Here we
investigate the impact of crystallization of prototypical porphyrins on the electronic levels and optical
properties in the framework of density functional theory and many-body perturbation theory.
Crystallization substantially shrinks the HOMO?LUMO gap based on polarization effects. We find a shift
of the HOMO to higher energy is consistent with recent experiment of MgTPP multilayer film on
Ag (100) [A. Classen et al., Phys. Rev. B, 2017, 95, 115414]. Calculated excitation spectra demonstrate a
significant redshift of excitation bands except for the Q bands. These lowest excitation bands, in stark
contrast to the strong HOMO?LUMO gap renormalization, remain essentially the same as in the gas
phase. Our work underlines the possibility of band-gap engineering via ligand-controlled modification of
the polarizability.
Forschungs-