A back-to-back diode model applied to MoS2 van der Waals Schottky diodes

The use of metal van der Waals contacts and the implicit reduction in Fermi-level pinning in contacted semiconductors has led to remarkable device optimizations. For example, using graphene as an electrical contact allows for tunable Schottky barriers in transistors and barristors. In this study, we present a double Schottky barrier model and apply it to barrier tunable all van der Waals transistors. In a molybdenum disulfide (MoS_2) transistor with graphene and few-layer graphene contacts, we find that the model can be applied to extract Schottky barrier heights that agree with the Schottky-Mott rule from simple two-terminal current-voltage measurements at room temperature. Furthermore, we show tunability of the Schottky barrier in-situ using a regional contact gate. Our results show that a basic back-to-back diode model, applied to two terminal measurements, can capture the diode properties of all-van-der-Waals transistors relatively well.