Gate induced charge transfer and hysteresis enlargement in MoS/GeSe vertical heterostructures

Two-dimensional van der Waals heterostructures provide an amazing platform to study the fundamental physical properties and build optoelectronic devices because of their abundant band structures and clean interface. In this paper, a MoS 2 /GeSe 2 vertical heterostructure is built with type I band alignment, and the hysteresis voltage reaches 94 V under the scan range of ±80 V. The large hysteresis is attributed to the charge transfer between the MoS 2 and GeSe 2 layers according to a series of investigations, which is beneficial for its application in memory devices. The understanding of the mechanism will be helpful to improve the device performance and develop other new van der Waals heterostructure devices. We explored the hysteresis enlargement in the vertical MoS 2 /GeSe 2 van der Waals heterojunction, and it was attributed to the gate induced charge transfer process between the MoS 2 and GeSe 2 layers.