Robust p-type ohmic contact in ZrI2/Dirac semi-metal van der Waals heterostructures

Abstract

For high-performance nanoelectronic devices, choosing the appropriate and reliable electrode contact material is of vital importance. Through first-principles calculations, we have systematically investigated the geometric structural stability and electronic contact properties between monolayer 2H-phase ZrI₂ and two-dimensional Dirac semi-metals. The results indicate that ZrI₂/semi-metal heterostructures are highly stable. All heterostructures exhibit p-type ohmic contacts, and the characteristic remains unaffected by variations in interlayer spacing, exhibiting strong robustness, which is extremely friendly to the fabrication of devices. The electrostatic potential and differential charge analysis show that due to the higher work function of the semi-metal compared to that of the semiconductor and the van der Waals interaction, electrons transfer from the semiconductor side to the semi-metal side, forming a built-in electric field pointing from the semiconductor to the semi-metal at the contact interface. Our research provides critical insights into selecting appropriate electrode contact materials for ZrI₂ and offers valuable theoretical references for developing high-performance nanoelectronic devices.