Electronic Structures of AlGaN2 Nanotubes and AlN-GaN Nanotube Superlattice.

The electronic properties of single-wall AlGaN2 nanotubes were investigated using first-principles calculations and generalized gradient approximation. All AlGaN2 nanotubes considered are semiconductors, but their band structures depend on their chirality and size due to curvature effect and symmetry. The zigzag AlGaN2 nanotubes are direct band gap semiconductors, while armchair AlGaN2 nanotubes are indirect band gap semiconductors. The calculations on the electronic properties of AlN-GaN nanotubes superlattice show that the band gap engineering can be realized by changing the composition of the AlN-GaN nanotubes superlattice.