Transport Studies of Boron-Doped Diamond/Graphene Heterostructures

Diamond/graphene heterostructures may enable novel devices that operate at high temperatures. As a first step towards realizing such devices, boron-doped diamond thin films were grown in a microwave plasma-assisted chemical vapor deposition (CVD) system on a tantalum substrate. Mechanical transfer of the diamond films onto graphene grown by CVD on a Si/SiO₂ substrate allowed us to fabricate heterostructure devices. We measured the current-voltage characteristics of the devices versus temperature, finding behavior consistent with thermally activated transport over a barrier of ~20 meV. This indicates that the contact barrier between graphene and doped diamond is relatively small. Variations in device behavior with diamond doping are possible, and our latest results will be discussed.