Adsorption characteristics of small aromatic molecules on silica/Ru(0001)

Organic molecules are part of future materials for electronic devices. The performance of these devices depends strongly on the atomic and electronic characteristics at the organic-substrate interface, which is necessary to provide support and/or conduction for the device. To develop a catalogue of anchor-group-dependent trends in these characteristics, we have undertaken a joint computational/experimental study of aromatic molecules (benzene, pyridine and thiophene) bound to Ru(0001), both with and without silica sheets inserted between the two. The silica sheets have been chosen to provide an experimentally accomplishable means of varying the separation between the adsorbate molecules and metal by growing them as monolayer or bilayer. Using DFT with vdW corrections, the models of above-mentioned systems will be presented along with their electronic properties (workfunction, charge transfer etc.). Accompanying, XPS measurements will provide complementary experimental data to compare electronic predictions. These will include changes in workfunction, valence-band measurements, and core-level XPS analysis with Auger Parameter analysis for improved deconvolutions of initial and final-state contributions to binding energy shifts.