title: Effect of water layer at the SiO2/graphene interface on pentacene morphology.
abstract: Atomic force microscopy has been used to examine early stages of pentacene growth on exfoliated single-layer graphene transferred to SiO2 substrates. We have observed 2D growth with mean height of 1.5 ± 0.2 nm on as-transferred graphene. Three-dimensional islands of pentacene with an average height of 11 ± 2 nm were observed on graphene that was annealed at 350 °C prior to pentacene growth. Compellingly similar 3D morphology has been observed on graphene transferred onto SiO2 that was treated with hexamethyldisilazane prior to the transfer of graphene. On multilayer graphene we have observed 2D growth, regardless of the treatment of SiO2. We interpret this behavior of pentacene molecules in terms of the influence of the dipolar field that emerges from the water monolayer at the graphene/SiO2 interface on the surface energy of graphene.
authors.affiliation: Laboratory of Organic Matter Physics, University of Nova Gorica , Vipavska 13, SI-5000 Nova Gorica, Slovenia.
authors.forename: Manisha
authors.initials: M
authors.lastname: Chhikara
authors.forename: Egon
authors.initials: E
authors.lastname: Pavlica
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Matković
authors.forename: Radoš
authors.initials: R
authors.lastname: Gajić
authors.forename: Gvido
authors.initials: G
authors.lastname: Bratina