Tetraphenylporphyrins at MgO(100): adsorption, level alignment,and the effect ofmulti-layer formation
Sprache des Vortragstitels:
ECOSS35 European Conference on Surface Science
Sprache des Tagungstitel:
Porphyrinsarekey elements in organic-inorganic hybrid systems for a widerange ofapplications [1,2]. Understanding their interaction with thesubstrate gives ahandle on structural and electronic device properties. Here weinvestigateCo(II)-tetraphenylporphyrin on the MgO(100) surface and theeffect ofmultilayer film formation within hybrid density functionaltheory and many-bodyperturbation theory. We focus on the relevant adsorptionsites, simulate theirphotoemission spectra as a key fingerprint and compare withexperiments on MgOfilms on Ag(100) . While we find only weak interactionbetween the cobaltcentre and terrace sites on the MgO(100) surface, a stronginteractionmanifests itself with the low-coordinated sites. This leads todistinctfeatures in both the valence and core-level regions of theelectronicstructure, as observed in the ultraviolet and X-rayphotoemission spectra,corroborated by simulated spectra and calculated cobaltcore-level shifts. Our work  thus demonstrates the relevance of morphology-relatedlow-coordinatedsites and their properties in the adsorption of CoTPP on theMgO(100) surface.