Center for Functional Nanomaterials Seminar

The application of the Resonant Photo Emission Spectroscopy (RPES) to various organic molecule based systems will be presented. The chemical specificity and the possibility to conduct experiments in the energy domain that provides a time scale for charge dynamics, make the RPES a powerful tool to study organic heterojunctions and in particular to probe the charge transfer processes at organic interfaces. The models used in RPES data analysis to extract the time scale of the excited charge delocalization and the spatial correlation of core, valence occupied and unoccupied molecular states will be briefly discussed. The application of RPES to some interfaces will be reported. In thin films of 3,4,9,10-perylene tetracarboxylic acid dianhydride (PTCDA) on (1x2) Au(110) surface organic layer metallicity is directly evidenced in RPES experiments. The case of ammine terminated organic overlayers will be discussed in connection with recent results of break junction experiments. Measurements carried out on ammine terminated organic molecules have been shown to provide for the first time reliable conductance measurements result on a wealth of molecules. In this case the comparison of RESPES and break junction results could elucidate the link between the quantum and the meso-scopic properties of such systems. To conclude the use of Resonant Photoelectron Diffraction as a tool to obtain structural information on low density emitter will be discussed.