Density Functional Theory Study on the Mechanical Properties and Interlayer Interactions of Multi-layer Graphene: Carbonic, Silicon-Carbide and Silicene Graphene-like Structures

The main purpose of this study is to calculate the Young's modulus of carbonic (c-graphene), silicon-carbide (SiC) and silicene graphene-like structures using density functional theory (DFT). Our results show that an increase in the number of layers did not noticeably change the Young's modulus of carbonic and silicon-carbide graphene, while the Young's modulus of silicene sheets decreased. Moreover, we found that carbonic graphene had the highest Young's modulus among the above-mentioned graphene sheets due to having the shortest distance between its elements. In contrast, silicene graphenes had the lowest mechanical properties and highest equilibrium Si-Si distance. We also investigated the existing van der Waals interfacial interaction between the layers of the multilayer graphene structure using the Lennard-Jones potential. We used the Lennard-Jones parameters (e and s) to model the van der Waals interaction as a classical linear spring. Finally, the densities of states (DOS) were calculated to better understand the electronic properties of these systems.