FORMATION OF ORDERED MOLECULAR OVERLAYERS BY A TEMPERATURE-INDUCED SURFACE REACTION: HEXABUTYLOXYTRIPHENYLENE ON Cu(111)

Abstract

Molecular monolayers obtained by the adsorption of hexabutyloxytriphenylene (HBT) on Cu (111) were investigated by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS) and thermal desorption spectroscopy (TDS). Adsorption at room temperature results in the formation of a disordered layer of physisorbed molecules. Annealing at temperatures of 600 K is found to induce a chemical reaction of the molecule with the substrate, leading to a desorption of the butyl fragments. This chemical reaction is accompanied by the formation of a highly ordered, well-defined oxytriphenylene layer which is stable for temperatures of up to 600 K.