Anomalous Reconfigurable-Transport in MoS2 Transistors by Electrically-Switchable van der Waals Interfacial Dipole

Interfacial charge transfer leads to the formation of an electric dipole at theinterface of a van der Waals (vdW) heterostructure. The switching of dipolepolarity using an electric field provides an effective method for modulating theelectronic properties of vdW systems. However, the experimental observationof switched vdW dipoles is challenging, as it is concealed by the electrostaticgating effect. In this work, the significant electrical tunability of the stronginterfacial dipole formed in an insulator-semiconductor heterostructure ofhigh-work-function BiOCl and MoS2 are demonstrated. The heterostructureddevice essentially operates as a planar tunneling transistor, whereband-to-band tunneling occurs within the vdW doping-defined junction,resulting in a subthreshold swing significantly lower than that of typicalfield effect transistors. More importantly, the anomalous reconfigurationof electronic transports is observed in MoS2 transistors due to the switchingof vdW dipole and its competition with the electrostatic gating. By varying theBiOCl thickness, the n-type, p-type, anti-ambipolar, and “W”-shaped transfercharacteristics are achieved. Furthermore, a dual-gate configuration furtherenhances functionality of the device, enabling multi-state switching, whichis of particularly interest for these applications requiring negative differentialresistance. This work offers a scalable, versatile, and non-destructivestrategy for tuning reconfigurable two-dimensional transistors.