Influence Of Bulk Doping Type On The Li Adsorption Site On Si(111)-(1x1): H

The model surface Si(111)-(1x1):H is used as a substrate for the adsorption of submonolayer amounts of Li. For n-doped substrates a peak right at the conduction band minimum is found in photoemission spectra. The peak is absent if the experiment is conducted on p-type substrates. Density functional theory calculations for different adsorption sites correlate this peak in the conduction band with Li adsorption in a H3 site of the Si(111)-(1x1):H surface. Experiment and theory show that the binding energy of the spectral feature is independent of the Li coverage. The absence of the structure for p-type substrates suggests a doping dependence of the adsorption site for Li on Si(111)-(1x1):H.