Theoretical investigations of a new two-dimensional semiconducting boron–carbon–nitrogen structure

A new two-dimensional boron–carbon–nitrogen (BCN) structure is predicted and is theoretically investigated based on density functional theory. The BCN structure belongs to the space group C222, and is composed of twelve B, twelve C and twelve N atoms per orthorhombic cell (named oC-B(12)C(12)N(12)). It consists of small hollow spheres with two hexagons per sphere. The dynamical, thermal and mechanical stabilities of oC-B(12)C(12)N(12) are respectively evaluated by phonon spectroscopy, ab initio molecular dynamics calculations and elastic constant measurements. The simulated in-plane stiffness and Poisson ratio display anisotropic features. The band structure shows that oC-B(12)C(12)N(12) is a direct semiconductor with a gap of 2.72 eV (GW). oC-B(12)C(12)N(12) has an absorption range from the visible light spectrum to the ultraviolet. Therefore, due to its small direct band gap and optical absorption, oC-B(12)C(12)N(12) may be a good candidate for electronic and optical applications.