Two-dimensional C₆X (X = P₂, N₂, NP) with ultra-wide bandgap and high carrier mobility

Abstract Two-dimensional (2D) materials with ultra-wide bandgap and high carrier mobility are highly promising for electronic applications. We predicted 2D C₃P, C₃N and C₆NP monolayers through density-functional-theory calculations. The phonon spectra and Ab initio molecular dynamics simulation confirm that the three 2D materials exhibit good phase stability. The C₃P monolayer shows excellent mechanical flexibility with a critical strain of 27%. The C₃P and C₆NP monolayers are ultra-wide bandgap semiconductors based on Heyd-Scuseria-Ernzerhof hybrid functional (HSE06) calculation. The C₃P monolayer has a direct bandgap of 4.42 eV, and the C₆NP and C₃N monolayer have indirect bandgaps of 3.94 and 3.35 eV, respectively. The C₃P monolayer exhibits a high hole mobility of 9.06 × 10⁴ cm²V⁻¹s⁻¹, and the C₃N monolayer shows a high electron mobility of 4.52 × 10⁴ cm²V⁻¹s⁻¹. Hence, the C₃P, C₃N, and C₆NP monolayers are promising materials for various electronic devices.