Few-layer graphene deposited on semiconductor nanorods separated by undoped
spacers has been studied in perspective for the fabrication of stable
nanoresonators. We show that an applied bias between the graphene layer and the
nanorod substrate affects the graphene electrode in two ways: 1) by a change of
the carrier concentration in graphene and 2) by inducing strain, as
demonstrated by the Raman spectroscopy. The capacitance of the investigated
structures scales with the area of graphene in contact with the nanorods. Due
to the reduced contact surface, the efficiency of graphene gating is one order
of magnitude lower than for a comparable structure without nanorods. The shift
of graphene Raman modes observed under bias clearly shows the presence of
electrostatically-induced strain and only a weak modification of carrier
concentration, both independent of number of graphene layers. A higher impact
of bias on strain was observed for samples with a larger contact area between
the graphene and the nanorods which shows perspective for the construction of
sensors and nanoresonator devices