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

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.