Coulomb drag transistor using a graphene and MoS2 heterostructure

Abstract

Two-dimensional (2D) heterostructures often provide extraordinary carrier transport as exemplified by superconductivity or excitonic superfluidity. Recently, a double-layer graphene (Gr) separated by few-layered boron nitride demonstrated the Coulomb drag phenomenon: carriers in the active layer drag carriers in the passive layer. Here, we propose high-performance Gr/MoS2 heterostructure transistors operating via Coulomb drag, exhibiting a high carrier mobility (∼3700 cm2 V−1 s−1) and on/off-current ratio (∼108) at room temperature. The van der Waals gap at the Gr/MoS2 interface induces strong interactions between the interlayer carriers, whose recombination is suppressed by the Schottky barrier between p-Gr and n-MoS2, clearly distinct from the presence of insulating layers. The sign reversal of lateral voltage clearly demonstrates the Coulomb drag in carrier transport. Hole-like behavior of electrons in the n-MoS2 is observed in magnetic field, indicating strong Coulomb drag at low temperature. Our Coulomb drag transistor thus provides a shortcut for the practical application of 2D heterostructures.