Exfoliating from high-pressure arsenic–nitrogen compounds: an efficient way to obtain 2D-AsN

Abstract

AsN compounds show potential for optoelectronic applications and are considered promising candidates for solar cell materials. Here, new arsenic–nitrogen compounds (i.e., AsN, As₂N₃, AsN₃) have been identified under pressure by first-principles calculations. We find that the cubic phase of reported AsN compounds transforms into the newly discovered layered Cmc2₁ phase at 19 GPa and then transitions to the Pnma phase at 63 GPa. Both layered structures are semiconductors and exhibit dynamic and mechanical stability at 0 GPa, suggesting potential for quenching to ambient pressure. Furthermore, two-dimensional AsN with a structure similar to black phosphorus is proposed to have excellent multifunctionality; however, it has not yet been synthesized. We propose a method to exfoliate monolayer AsN from a layered structure and find that the exfoliation energies of AsN compounds are at least 1 meV Å⁻² lower than those of graphene and phosphorene. These findings shed light on the formation conditions and properties of AsN compounds and provide valuable insights for future experimental synthesis.