Stacking and species ordering depended electronic properties of SiC/GeC bilayer heterostructur

Two dimensional polar materials, such as SiC or GeC monolayer, possess an in-plane charge transfer between different elements due to their different electron negativities. It is still not clear how the in-plane charge transfer plays a role when these polar materials are stacked vertically forming 2D polar heterostructures. In this work, we have systematically investigated this issue at the first principle level and found that, in addition to the vdW weak interaction, the electrostatic force triggered by such in-plane charge transfer could induce the π-π orbital hybridization between adjacent layers and forming electrostatic interlayer bonding which strongly depends on the stacking arrangement and the out-of-plane species ordering between layers. This additional interaction is the reason of the existence of tunable electronic properties by altering the stacking and species ordering. More interestingly, we found that the net spatial charge redistribution in the interfacial region leads to a built-in electric field, which could reduce the probability of photo-generated carrier recombination, making such polar heterostructures a promising candidate in the application of nanoelectronics