Abstract
Electronic properties of cubic boron nitride (c-BN) doped with group IIA elements were systematically investigated using the first principle calculation based on density functional theory. The electronic bandgap of c-BN was found to be narrowed when the impurity atom substituted either the B (IIA -> B) or the N (IIA -> N) atom. For IIA -> B, a shallow accept level degenerated into valence band (VB); while for IIA ! N, a shallow donor level degenerated conduction band (CB). In the cases of IIBe -> N and IIMg -> N, deep donor levels were also induced. Moreover, a zigzag bandgap narrowing pattern was found, which is in consistent with the variation pattern of dopants' radius of electron occupied outer s-orbital. From the view of formation energy, the substitution of B atom under N-rich conditions and the substitution of N atom under B-rich conditions were energetically favored. Our simulation results suggested that Mg and Ca are good candidates for p-type dopants, and Ca is the best candidate for n-type dopant. (c) 2018 Author(s).