Interface formation of phenylacetylene with Cr investigated by XPS

Summary form only given. The interface formation between metal and polymer has been studied by X-Ray photoelectron spectroscopy for the Chromiuni/polyphenylacetylene (PPA) system, using the monomer (Phenylacetylene-PA) as a model molecule for PPA. The use of a single molecule allows to work on a simplified system which gives more chances for the understanding of the interaction occurring during the early stages of interface formation. It has been found that upon PA vapor deposition onto a Cr clear substrate, at very low PA coverage, a low energy tail appear at the C 1s core level photoelectron peak in a limited extent. The observed behaviour is interpreted as due to charge transfer process from the metal substrate into the carbon atoms of PA that gives rise to a negatively shifted C 1s core level peak. The charge-transfer interaction by Cr and PA is not evidenced by the analysis of the Cr 2p/sub 3/2/ core level peak which exhibits the same features as for bulk Cr. The interaction between Cr and PA condensed as a thick layer as also been investigated.