Figure 3
From: Split-gated point-contact for electrostatic confinement of transport in MoS2/h-BN hybrid structures
(a) Dependence of pinch-off voltage on the drain-source voltage for VBG = 2 V (blue) and 10 V (green) at 4 K. Upper inset: pinch-off curves at three different VDS, 0.61 V (red), 0.72 V (green) and 0.89 V (blue) with VBG = 10 V. x-axis is VSG in Volts and y-axis is the current through the device in nA. Lower inset: an enlarged view of the pinch-off region. (b) A surface plot of pinch-off characteristics at 4 K for a series of VBG with the on-state current kept as 50 nA for each trace. The regime-III, the shoulder, enclosed by the pink dashed lines show a shift in the position and a reduction in the span in VSG as VBG is reduced. The illustrations marked by the arrows show the available states for transport at the onset of point-contact formation for higher (VBG = 10 V) and lower (VBG = 0 V) carrier concentrations. (c) Variation of the pinch-off voltage with VBG. The red trace represents the pinch-off voltage extracted from (b), and the black trace from pinch-off characteristics taken with a VDS of 1 V. (d) Pinch-off characteristics for another point-contact device at 300 K for various VBG values. The arrow indicates the linear shift in the position of the shoulder like structure with the VBG. Inset: Optical image of the device, scale bar is 20 μm.
