Observation of outermost surface layer of 4-mercaptohydrocynnamic acid self-assembled film on Au(111) by Penning ionization electron spectroscopy

Penning ionization electron spectroscopy (PIES) and ultraviolet photoelectron spectroscopy (UPS) were used to characterize the self-assembled (SA) film of 4-mercaptohydrocynnamic acid deposited on Au(111) from aqueous solution. The analysis of the relative band intensity of the Penning spectra suggests that the molecules expose the thiophenyl group outside the film surface, and form a bilayer made up of a hydrogen-bonding network of carboxyl groups. (C) 1999 Elsevier Science B.V. All rights reserved.