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.