Thickness-dependent Schottky barrier height of MoS 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 MoS-metal contacts decreases with the thickness of MoS. We obtained a Schottky barrier height as low as about 70 meV when MoS is trilayer-thick. It is important to find the optimal choice of contact metal and layer thickness of MoS.