Anomalous Coulomb drag behavior in graphene/MoS₂ heterointerface

Two-dimensional (2D) heterointerface often provides extraordinary carrier transports exemplified by superconductivity or excitonic superfluidity. Recently, double-layer graphene separated by few-layered boron nitride demonstrates Coulomb drag phenomenon that carriers in active layer drag carriers in passive layer. Here, we propose a new switching device platform operated via Coulomb-drag interaction at graphene/MoS₂ (GM) heterointerface. Ideal van der Waals distance allows for strong coupling of interlayer electron-hole pairs whose recombination is prevented due to the Schottky barrier built by charge transfer at heterointerface. This GM device exhibits high carrier mobility of up to ~3,700 cm²V^-1s^-1 via electron-hole Coulomb drag even at room temperature, while retaining high on/off current ratio of ~10⁸, outperforming those of individual layers. In electron-electron drag regime, we observe graphene-like Shubnikov-de Haas oscillations in GM device at low temperature. Our Coulomb-drag transistor could be a shortcut to realize the practical applications of quantum-mechanical 2D heterostructures at room temperature.