Tunneling Mechanism in Ultimate Thin Vertical Au/MoS2/Au Tunnel Junction*

This study illustrates the nature of electronic transport and its transition from direct tunneling to Fowler Nordheim tunneling between a metal electrode and MoS2 channel interface in a vertical tunnel device configuration. We developed a fabricating procedure to prepare vertical tunnel junction based on 2D transition metal dichalcogenides sandwiched between two ultra-flat Au substrates. We prepared ultra-flat gold electrodes using template stripping. The devices were prepared by dry transfer technique. We studied many devices with varying thickness from monolayer to few layers MoS2. We studied the transition between Fowler-Nordheim tunneling and direct tunneling signatures at different temperature ranging from 77K to room temperature allowing us to extract the Schottky barrier height precisely. We found that the Schottky barrier height depends on the temperature and layer numbers.