The graphene-on-diamond structure with Ni-catalyzed under high temperature

Graphene-on-diamond (GOD) composite structure has been attracting considerable attention due
to the unique features for all carbon sp3-sp2 electronic applications. Whereby the electrical
properties of diamond surface can be purposely tailored and significantly altered through
transformed graphene layers. In this work, graphene-on-diamond composite structures were
prepared by nickel-catalyzed high-temperature rapid annealing, and were analyzed by Raman,
Hall effect measurement and Transmission electron microscopy (TEM). The results show that the
difference in surface conductivity of graphene-on-diamond composite structure is mainly related
to the number of transformed graphene layers, while the number of layers is mainly affected by
annealing time and the thickness of nickel film. Hall measurement and TEM results show that
when the transformed graphene becomes graphite with a lot of Ni atoms embedded into diamond,
the surface carriers of graphene-on-diamond composite structure are electrons. On the contrary,
when the transformed graphene is about 3 or 5 layers, the surface carriers are holes. These
findings may provide a route for graphene-on-diamond structure to become a strong candidate
for next generation complementary diamond electronic devices.