The electron properties of infinite length single-walled silicon nanotubes are studied by density functional theory

For all the armchair SWSiNTs, the infinite zigzag SiNTs (n,0), (3 ≤ n ≤ 9) and the infinite chiral SWSiNTs (6, 2), (9, 3), (10, 5), (12, 6) are semiconductors with indirect band gaps. While for the infinite zigzag SiNTs (n, 0) 15 ≥ n ≥ 10, and the infinite chiral SWSiNT (12, 4) are semiconductors with direct gaps at Ｘ point, the direct gaps open at Ｘ point. It is possible that direct band gap will become potential building blocks for electronic and optoelectronic devices.