HREELS CHARACTERIZATION OF SURFACES AND INTERFACES IN SELF-ASSEMBLED MOLECULAR MONOLAYERS

High resolution electron energy loss spectroscopy (HREELS) is used to characterize the extreme surface composition and the interfaces of sil ane and thiol monolayers deposed on silicon and platinum crystals, res pectively. Energy losses due to impact interactions are very sensitive to the molecular groups present in the extreme surface of the film. L ong range dipole interactions can supply information about buried inte rfacial bonds. Silicon substrates were characterized before and after molecular interactions, Energy losses assigned to interfacial siloxane bonds clearly vary with previous substrate annealing. Spectra of adso rbed thiols are dominated by losses corresponding to functional groups attached to the chain-end. An energy loss at 360 cm(-1) was identifie d as corresponding to an interfacial S-Pt bond. (C) 1998 Elsevier Scie nce S.A. All rights reserved.