Thickness-dependent Schottky Barrier Height of MoS2 Field-effect Transistors

2D semiconductors, including transition metal dichalcogenides (TMDs), have been widely studied recently. However, the device performance is deteriorated due to the significant contact resistance. The contact resistance of MoS2-metal contacts decreases with the thickness of MoS2. We obtained a Schottky barrier height as low as about 70 meV when MoS2 is trilayer-thick. It is important to find the optimal choice of contact metal and layer thickness of MoS2.