Atomic defects (vacancy, substitutional, and Stone-Wales) in monolayer aluminum nitride: A density-functional-theory simulation

Aluminum nitride (AlN) is a mechanically strong material with a high melting point and excellent thermal conductivity. In this study, the AlN is modeled with defects in vacancies, substitutions, and Stone-Wales using a density functional theory (DFT). We model six configurations, two configurations of monovacancies: aluminum vacancy (VAl) and vacancy nitrogen (VN), two configurations of substitutions: aluminum substitution (SN→Al) and nitrogen substitution (SAl→N), the interchange (IAl "N), and Stone-Wales (S-W). We find structural changes in each defect with outward relaxation and VN with inward relaxation. the band structure calculations show that the geometric structure introduces new states near the Fermi level except for the VAl system.