The transfer process of graphene onto the surface of oxide substrates is well known.
However, for many devices, we require high quality oxide thin films on the surface of
graphene. This step is not understood. It is not clear why the oxide should adopt the
epitaxy of the underlying oxide layer when it is deposited on graphene where there is
no lattice match. To date there has been no explanation or suggestion of mechanisms
which clarify this step. Here we show a mechanism, supported by first principles
simulation and structural characterisation results, for the growth of oxide thin films on
graphene. We describe the growth of epitaxial SrTiO3 (STO) thin films on a graphene
and show that local defects in the graphene layer (e.g. grain boundaries) act as bridgepillar
spots that enable the epitaxial growth of STO thin films on the surface of the
graphene layer. This study, and in particular the suggestion of a mechanism for
epitaxial growth of oxides on graphene, offers new directions to exploit the
development of oxide/graphene multilayer structures and devices.