Structural and Energetic Landscape of Polar SiC Bilayers: A Computational Study of the Potential Energy Surface

Understanding the Potential Energy Surface (PES) corrugation is fundamental to characterizing the stability and interlayer interactions of two-dimensional (2D) van der Waals materials. This research uses first-principles calculations and geometry optimization to investigate the structural stability and atomic geometry of a polar Silicon Carbide (SiC) bilayer. The study systematically maps the PES, exploring the influence of (AA/AB) stacking and species ordering by analyzing lateral displacement and equilibrium interlayer distance. Key findings show that structural stability depends critically on the relative positioning of Si and C atoms across the interface. The lowest energy configuration consistently occurs at an exceptionally short interlayer distance, maximizing the electrostatically favorable Si-C interaction. This underscores the crucial role of electrostatic interlayer interaction in governing the stability of the polar SiC bilayer. A strong correlation is also established between PES minima and the corresponding interlayer equilibrium distance. These results offer robust, quantitative insights into bonding characteristics and confirm the intrinsic structural stability of the optimized SiC structure, advancing the fundamental understanding of 2D polar SiC for next-generation electronics and optoelectronics.