ABSTRACT
This chapter reports on the first experimental observation of terahertz emission and detection in a double graphene layered (GL) heterostructure which comprises a thin hexagonal-boron nitride tunnel-barrier layer sandwiched between two separately contacted GLs. It highlights a novel strategy for the realization of efficient voltage-tunable terahertz emitters and detectors. In particular, applications of graphene field effect transistors (GFET) operating in the terahertz (THz) range are appealing as it is one of the least explored frequency region and holds potential to revolutionize the fields of security, medical imaging, chemical sensing and high-speed wireless communication. The chapter also reports on the fabrication and first experimental observation of THz emission and detection in the double-graphene-layered heterostructures based on a thin h-Boron Nitride tunnel-barrier sandwiched between two monolayers of graphene. For instance, in the case of lateral GFET, only the electrons in top surface of graphene have freedom to receive incident energy and contribute to photo-generated current, thus limiting the sensitivity of such devices.
