Large-scale AlN nanowires synthesized by direct sublimation method

Hexagonal aluminum nitride (AlN) nanowires were fabricated by direct sublimation method without a catalyst layer. The obtained nanowires have diameters of about 30–100 nm and length up to tens of micrometers. TEM observation indicates that these nanowires are single-crystalline and grow along [0 0 0 1] direction. It is thought that vapor–solid (VS) mechanism should be responsible for the growth of AlN nanowires. In addition, room temperature Raman scattering and photoluminescence spectra from AlN nanowires were studied. Photoluminence spectrum of the AlN nanowires shows a wide emission band centered of 517 and 590 nm, which is related to N vacancies and the transition from the level of VN+ to ground state of the deep level of [VAl3− + 3ON+] defects, respectively.