Synchrotron radiation photoelectron spectroscopy study of Pb-Pc thin films on InSb(1 0 0)-(4×2)/c(8×2)

The electronic properties and the thermal stability of a thin film of lead-phthalocyanine deposited on the InSb(1 0 0)-(4×2)/c(8×2) surface were studied by synchrotron radiation core level and valence band photoelectron spectroscopy. The interaction between the overlayer and the substrate was determined by analyzing the photoemission spectra of a thin film and of a single monolayer of adsorbed molecules. Subsequently the monolayer was annealed at increasing temperatures, leading first to a gradual change of the oxidation state of the central lead atom, then to a fragmentation of the macrocycle itself.