On Transport in Vertical Graphene Heterostructures

We investigate charge transport through a vertical semiconductor-graphene-semiconductor heterostructure with quantum simulations using an atomistic tight-binding Hamiltonian within the nonequilibrium Green´s function formalism. We show that the normal transmission coefficient and therefore the current through the heterostructure can be greatly influenced by the atomically thin graphene layer, depending on the coupling between layers and on the k-space transmission overlap between graphene and the semiconductor. Our insights enable better understanding of transport through vertical heterostructure and highlight design parameters that might be used for the optimization of graphene-based heterostructure devices exploiting off-plane transport.