Anisotropic carrier mobility in single- and bi-layer C3N sheets

Based on the density functional theory combined with the Boltzmann transport equation with relaxation time approximation, we investigate the electronic structure and predict the carrier mobility of single- and bi-layer newly fabricated 2D carbon nitrides C₃N. Although C₃N sheets possess graphene-like planar hexagonal structure, the calculated carrier mobility is remarkably anisotropic, which is found mainly induced by the anisotropic effective masses and deformation potential constants. Importantly, we find that both the electron and hole mobilities are considerable high, for example, the hole mobility along the armchair direction of single-layer C₃N sheets can arrive as high as $1.08\times {10}^4$ cm² V⁻¹ s⁻¹, greatly larger than that of C₂N-h2D and many other typical 2D materials. Owing to the high and anisotropic carrier mobility and appropriate band gap, single- and bi-layer semiconducting C₃N sheets may have great potential applications in high performance electronic and optoelectronic devices.