Modifying the electronic and geometrical properties of mono/bi-layer graphite-like BC2N via alkali metal (Li, Na) adsorption and intercalation: computational approach

Abstract

The boron/carbon/nitrogen-based materials have received much attention in condensed matter physics and material sciences due to their novel optoelectronic properties. Using first-principles calculations, we investigate the structural and electronic properties of Li and Na atoms intercalated onto the mono- and bilayer of BC₂N sheets. The results show that both monolayer and bilayer BC₂N exhibit nonmagnetic ground states with direct band gaps of 1.08 and 0.45 eV, respectively. The negative adsorption energies (in the range of ∼−0.76–−2.62 eV per atom) of 1L/2L-M_n©BC₂N (M = Li, Na; n = 1, 2, 3) indicated that these structures are thermodynamically stable. The intercalation of Li and Na metal atoms into the bilayer BC₂N is more favorable than the monolayer BC₂N and also the Li intercalation is better than the Na intercalation. In the most stable configurations of Li_n©BC₂N, the metal atoms located on the center of the carbon hexagonal ring (H₁ site) while for the Na_n©BC₂N, it prefers to locate above the C atoms or C–C bond. Based on the calculated electronic properties such as PDOS, planar average charge density difference and Bader charge analysis, it can be seen that the Li and Na alkali metals donate electrons to 1L/2L-BC₂N sheets and 1L/2L-M_n©BC₂N structures have metallic behavior. These findings suggest that the 1L/2L-M_n©BC₂N structures are promising candidates for host materials with potential applications in nanoelectronics and energy storage.