Interfacial properties of two-dimensional graphene/ZrS_2 and ScS_2/ZrS_2 contacts

摘要

The two dimensional device is a promising candidate for preparation of 'More than Moore' device. However, two dimensional device always exhibits relative weak on-current. In this work, graphene and monolayer ScS2 are used as metal electrode to contact with monolayer ZrS2. Using the first principle calculation, we analyze the electronic structures of the different types of metal/ZrS2 contact and figure out how the orbital coupling and charge transfer influence the interface barrier. The Ohmic contact can be obtained in vertical graphene/ZrS2 and in-plane ScS2/ZrS2 contacts, implying high carrier injection efficiency can be achieved in the contacts. The tunneling probability is larger than 97% in all the contacts. Moreover, the strain can modulate the interfacial dipole moment and the mutual transformation of Schottky contact and Ohmic contact. In particular, compressive strain is conducive to improve the carrier injection efficiency. In addition, a low resistance junction is designed based on ScS2/ZrS2/graphene contact and the multifunction of the junction may be achieved with electrostatic doping. The results provide guidelines for designing low-resistance two dimensional ZrS2 device.