Band engineering realized by chemical combination in 2D group VA–VA materials

Abstract

Two-dimensional (2D) group VA materials share classical configurations, buckled and puckered honeycomb structures, with intriguing wide electronic properties that have attracted great research interest. The chemical combination of different group VA elements can realize the band engineering of 2D group VA materials owing to their distinct atomic radii and electronegativities. Based on first principles calculation, we present a detailed theoretical investigation of these 2D group VA–VA materials with buckled and puckered structures, including atomic structure, energy stability, and electronic properties. These 2D group VA–VA materials showed appreciable cohesive energies comparable to 2D group VA materials, and were semiconductors with a wide range of bandgaps from 0.49–2.82 eV. Seven of these materials showed an intrinsic direct bandgap. Interestingly, the bandgaps of the 2D group VA–VA materials showed a regular trend related to their atomic radii and electronegativities. In particular, Mexican-hat dispersion and Rashba spin splitting were present in the valence band and conduction band of the 2D buckled structures, respectively. Our comprehensive study further develops the 2D group VA materials family and provides promising candidates for optoelectronic and spintronic applications.