Interface configuration in goldrpolycarbonate bilayer structure: an in situ study through Arq ion depth profiling

The formation, configuration and the interactions at the goldrpolycarbonate AurPC.interface formed by thermally evaporated Au on PC film, a technologically important polymer, is studied by X-ray photoelectron spectroscopy XPS.at an Au thickness of 35.4 A° . XPS depth profiling with 3 keV Arq ion sputtering at 1 mA revealed the interface between the as-deposited 35.4 A° Au film and the PC substrate to be sharp covering a few monolayers. A substantial Au atomic concentration of ;3% in the bulk PC indicated that Arq ion assisted diffusion of the metal into the bulk. Existence of weak AuªC charge transfer interactions with Au as the electron injector distributing a net charge density at the C5O as the primary interaction site was deduced from the appearance of the 282.6 eV C1s feature, thus resulting in the formation of Au–CO p back bond. The sputtering experiments revealed the growth-mode of Au on PC to proceed by metal monolayer deposition followed by cluster growth on the already weakly bonded Au onto the C5O carbon of the polymeric backbone. q1999 Elsevier Science B.V. All rights reserved.