Vertical Heterostructure of 2D Polar Binary Compounds(GeC/SiGe): First- Principles study

It is well known that vdW interaction plays a major role between adjacent layers in 2D vertical heterostructures. However, our preliminary study shows that the in-plane charge transfer between elements in 2D polar materials, such as SiGe or GeC monolayer, opens our mind to understand the effect of the electrostatic force triggered by such in-plane charge transfer when design vertical heterostructure build by polar monolayers. Our systematic analysis pointed out that, in addition to the vdW weak interaction, there is an electrostatic interlayer bonding formed by the orbital hybridization in the interlayer region which has a strong effect on the structural and electronic properties of such vertical polar heterostructures and shows the ability to modify them by the different staking constituent’s arrangement. More interestingly, we found a built-in electric field in the interlayer region build by the charge redistribution, which may affect the probability of photo-generated carrier recombination. These promising results make such polar heterostructures a bright candidate in the application of nanoelectronics.