The copper phthalocyanine/Au(1 0 0) interface studied using high resolution electron energy-loss spectroscopy

The vibrational and electronic excitations of copper phthalocyanine (CuPc) sublimed as a highly ordered thin films on Au(1 0 0) have been studied using high-resolution electron energy-loss spectroscopy. The vibrational modes of submonolayer, monolayer and multilayer CuPc films show strong differences in intensity for in- and out-of-plane modes which demonstrates the well ordered film structure. In addition, the interaction between CuPc and Au at the interface is very weak which is indicated by an only very small frequency shift of the vibrational modes and no substantial changes as regards the electronic excitations. Consequently, this interface can be regarded free of interface states.