Theoretical prediction of novel two-dimensional planar aluminum nitride allotropes: first principles calculations

This paper uses first principles calculations based on density functional theory to predict the possibility or ability to synthesize two-dimensional planar allotropes of aluminum nitride, as well as study their structural and electronic properties. The investigated systems include six allotropes in which the atoms of aluminum and nitrogen participate in chemical bonds with sp(2) and sp(1) + sp(2) hybridization. After the structural relaxation, all these allotropes-despite being less stable than the graphene-like aluminum nitride allotrope-still retain their original structure. The degree of structural stability of these allotropes depends on the hybridization of the constituent atoms and the number density of atoms per unit cell. Regardless of the structure type and the hybridization of the atoms, all these allotropes are semiconductors; however, the amount and type of energy gap varies for different structures.