Hard-breakable Ohmic contact in 2D CrSi2N4-metal heterostructures: A DFT study

Abstract

The interface barrier in van der Waals heterostructures (vdWHs) determines the charge-transfer efficiency and, thus, affects the performance of electronic devices. In this work, we propose two novel 2H–CrSi2N4 and 1T–CrSi2N4 monolayers that can form Ohmic contact heterostructures with other monolayers, including graphene, Ti2C, NbS2, and Ti3C2, based on first-principle calculations. First, we studied 2H–CrSi2N4 and 1T–CrSi2N4 contact with the widely used graphene, and the calculation results show that these heterostructures can form Ohmic contact with zero potential barriers, a desirable property to achieve high-performance electronic devices. Interestingly, this kind of Ohmic contact can be well maintained under electric fields, indicating a great potential for practical applications. On the other hand, 2H–CrSi2N4 and 1T–CrSi2N4 also form Ohmic-contact heterostructures with the Ti2C, NbS2, and Ti3C2 monolayers via vdW interaction. These interesting phenomena of vdWHs can provide enlightenment for designing high-efficiency electronic devices.