Molecular switching operation in gate constricted interface of MoS2 and hBN heterostructure

Abstract

Combined with diverse two-dimensional (2D) materials for semiconductor interfaces are attractive for electrically controllable carrier confinement to enable excellent electrostatic control. We investigated the transport characteristic in heterointerface of multilayer molybdenum disulfide and hexagonal boron nitride (MoS2/h-BN) to reveal that the charge transfer switching (CTS) is highly dependent on both the local gate constriction and bias applied across the channel. Notably, the CTS is controlled at a molecular level through electrotunable gated constriction. The resulting significant change in conductance due to exposing 100 parts-per-billion of nitrogen dioxide molecules led to a high on/off ratio of 102 for completely switching off the channel thus, acting as a molecular switch. First-principle calculations further explained the mechanism of molecular CTS in the device. The molecular tunability of CTS has not been previously reported in any of the hetero semiconductor interfaces. Our finding opens avenues to exploit various atomically thin heterostructures for the mesoscopic transport phenomena towards molecular switching operation at room temperature.