Ab-initio investigations on the energetic, opto-electronic and magnetic characteristics of alkali metal (AM) atom substituted monatomic AlN layer

Physical properties of AM atom substituted monolayer AlN are studied using first-principles calculations. During Li@Al substitution, AlN carries narrow/wide (0.3/2.95 eV) band gaps for spin up/down bands. The Na@Al substitution produces thin band semiconductor with (1.9/1.3 eV) energy gaps during spin up/down bands, respectively. Both K@Al and Na@N doping in AlN produced (0.5/0.4 eV) band gaps, respectively. The Li@N doped AlN is a half metal/wide band semiconductor for spin up/down bands, respectively. The K@N doped system displays (0.7/0.8 eV) energy gaps through spin up/down bands, respectively. Various optics parameters are improved in low energy range for all AM-doped AlN systems.