Crystallographic orientation dependence of work function: carbon adsorption on Au surfaces
Dustin A. Hite, Hossein Jooya, X Fan, Kyle S. McKay, David P. Pappas, H.R. Sadeghpour
We show in this work that the work function change due to carbon adatom adsorption is not predominantly affected by the crystallographic orientation of the gold surface. Ab-initio calculations within density-functional theory are performed on carbon deposited (100), (110), and (111) gold surfaces. The work function behavior with carbon coverage for the different surface orientations is explained by the resultant electron charge density distributions. Although the carbon adsorption at submonolayer coverage is dictated by different potential energy landscapes of these surfaces, at higher coverage, all the three orientations would impose approximately the same work function, associated with the work function of the bulk adsorbate, i.e. graphite. This systematic study provides a detailed understanding of the components of polycrystalline gold that have been largely employed in miniaturized electrodes.