Regensburg 2019 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 54: Organic Molecules on Inorganic Substrates III: Magnetism, Doping and Interfaces

O 54.8: Vortrag

Mittwoch, 3. April 2019, 12:15–12:30, H24

Addressing the NTCDA/Ag(111) interface state in large unit cells within ab-initio calculations — •Lukas Eschmann, Peter Krüger, and Michael Rohlfing — Institut für Festkörpertheorie, Westfälische Wilhelms-Universität, 48149 Münster, Germany

Molecular adsorption causes interaction between the electronic structure of adsorbate and substrate. One particular case is the energy shift of the Shockley surface state on Ag(111) and other surfaces: upon adsorption of organic molecules the state turns into an interface state leading to a change in dispersion and a shift to higher energy by as much as ∼ 0.5 eV.

Here we address the interface state between the Ag(111) surface and adsorbed NTCDA within density-functional theory (DFT). To identify the dispersion of the interface state we have developed a projection technique which maps the states of the adsorbate system onto the original Shockley state. The projection also handles the loss of the surface periodicity due to the adsorbate, thus recovering the parabolic dispersion of the interface state in its original periodicity. We find that the energy shift of the Shockley state, as well as changes of its effective mass, are proportional to the adsorption coverage. Using our technique we also see a strong anisotropy in the dispersion of the state.