2D Boron Carbide, Carbon Nitride, and Silicon Carbide: A Theoretical Prediction

Two-dimensional (2D) boron carbide, carbon nitride, and silicon carbide are proposed with the aid of the density functional theory (DFT) simulations. These 2D systems are actually designed by doping the corresponding heteroatoms in the 2D Me-graphene (also called C568) system. Their structural stabilities are verified by analyzing their phonon relations. The mechanical strength of the Me-graphene-like silicon carbide (Me-C8Si4C) is weakened to some extent compared with the pristine Me-graphene, while the mechanical property of the proposed boron carbide (Me-C8B4C) is much enhanced. Moreover, according to our calculations at the HSE06 level, the Me-C8B4C system is metallic, while the proposed carbon nitride (Me-C8N4C) and silicon carbide (Me-C8Si4C) are semiconductors. Especially, the Me-C8N4C system exhibits a moderate band gap of 1.869 eV at the HSE06 level, which implies its application potentials in the solar conversion and photocatalysis fields. Furthermore, the influences of the biaxial strains on these designed systems are also discussed.