Striped Domains At The Pentacene:C-60 Interface

Scanning tunneling microscopy observations of the initial growth stages of the first layer of pentacene on a monolayer film of C-60 on Ag(111) are presented. Pentacene films nucleate and grow with molecules standing up at the pentacene:C-60 interface similar to thin film phases observed on weakly interacting substrates such as SiO2. Unlike reported thin film pentacene phases, those on 1 monolayer C-60/Ag(111) exhibit a striated morphology with domains of 4 nm nominal width. This long range pattern of periodic pentacene displacements relative to the substrate is the response to stress induced in the pentacene film by its interaction with the rigid C-60 support.