Structure and Electronic Properties of Saturated and Unsaturated Gallium Nitride Nanotubes

The atomic and electronic structures of saturated and unsaturated GaN nanotubes along the [001] direction with (100) lateral facets are studied using first-principles calculations. Atomic relaxation of nanotubes shows that appreciable distortion occurs in the unsaturated nanotubes. All the nanotubes considered, including saturated and unsaturated ones, exhibit semiconducting, with a direct band gap Surface states arisen from the 3-fold-coordinated N and Ga atoms at the lateral facets exist inside the bulklike band gap. When the nanotubes are saturated with hydrogen, these dangling bond bands are removed from the band gap, but the band gap decreases with increasing the wall thickness of the nanotubes.

National Natural Science Foundation of China 10704014 Young Scientists Foundation of Sichuan 09ZQ026-029 UESTC JX0731 Chinese Academy of Sciences U.S. Department of Energy DE-AC05-76RL-01830 Z. Wang was financially supported by the National Natural Science Foundation of China (10704014) and the Young Scientists Foundation of Sichuan (09ZQ026-029) and UESTC (JX0731). J. Li gratefully acknowledges financial support from the