Tensile strain effects on C4N3H monolayer: Large Poisson's ratio and robust Dirac cone

Abstract

Recently, a novel two-dimensional (2D) metal-free organic material, the C4N3H monolayer, has been proposed and predicted to be a 2D Dirac material with high Fermi velocities. Herein, we investigated its mechanical properties and tensile strain effects on its electronic properties based on first-principles calculations. We demonstrated that this material is quite soft with small stiffness constants and can sustain large strains. Compared to many other 2D materials, this material presents a remarkable elastic anisotropy and a large Poisson's ratio, which are very important for strain engineering. We also found that the Dirac cone of this material is very robust against the tensile strains and the Fermi velocity is high. The small stiffness constant, large Poisson's ratio, robust Dirac cone, and high Fermi velocity make the C4N3H monolayer a promising material in high-speed flexible electronic devices.