Interface Dipole and STS comparisons

[JadenErius]

Hi again people!

So if I have two STS (scanning tunneling spectroscopy) spectra, one taken on a substrate and the other one taken on an adsorbate layer ontop of the substrate. Assuming there is some sort of interfacial dipole that forms between the substrate and the adsorbate layer, can I compare peak positions directly between the two spectra?

i.e. This peak is the LUMO of adsorbate and this other peak is the CBM of the substrate

 

[BigJDubs]

? It depends on the type of STS spectra. Generally speaking, it can be difficult to compare peak positions between two STS spectra because the presence of an adsorbate layer may affect the electronic states of the substrate. In addition, the adsorbate layer may also introduce its own electronic states that are not present in the substrate. Therefore, it is best to take additional measurements or use other methods to confirm the assignment of the peaks to the substrate and adsorbate.