Modulation of Schottky barrier height in graphene/MoS2/metal vertical heterostructure with large current ON-OFF ratio

TL;DR

This study investigates how applying a gate voltage to graphene in a graphene/MoS2/metal heterostructure modulates the Schottky barrier height, enabling control of current flow and achieving a large ON-OFF ratio.

Contribution

It demonstrates direct modulation of Schottky barrier height via gate voltage in a graphene/MoS2 heterostructure, with analysis of layer dependence and temperature effects.

Findings

Schottky barrier height can be modulated by gate voltage.

Layer number of MoS2 affects barrier modulation.

Larger barrier modulation leads to higher current ON-OFF ratio.

Abstract

Detail transport properties of graphene/MoS2/metal vertical heterostructure have been investigated. The van der Waals interface between the graphene and MoS2 exhibits Schottky barrier. The application of gate voltage to the graphene layer enables us to modulate the Schottky barrier height; thus gives rise to the control of the current flow across the interface. By analyzing the temperature dependence of the conductance, the modulation of Schottky barrier height {\Delta}{\phi} has been directly determined. We observed significant MoS2 layer number dependence of {\Delta}{\phi}. Moreover, we demonstrate that the device which shows larger {\Delta}{\phi} exhibits larger current modulation; this is consistent with the fact that the transport of these devices is dominated by graphene/MoS2 Schottky barrier.