Elastic and electronic properties of C2N monolayer: first-principles calculation

In this paper, elastic constants, elasticity and the electronic properties of C2N monolayer are studied using density functional theory. The in-plane stiffness and the Poisson's ratio values tally with a similar graphitic two-dimensional carbon nitride sheet. The calculated critical point (elastic points) for both the uni- and bi-axial strains show that the C2N monolayer can withstand longer tensions in the elastic region more than that for heptazine sheet. Our results validate the mechanical stability of C2N monolayer. The band gap of the C2N monolayer is found to decrease under applied mechanical strains. The decrease in band gap is a result of a uniform high energy shift of p-like orbital including s orbital states towards fermi level. We find no change in the geometry and band gap size of the C2N monolayer under electric field up to a peak value of 10 V nm−1.