Growth and optical characterization of high-quality GaN nanobelts

Large quantities of high-quality GaN nanobelts were successfully grown on a Ni-coated LaAlO3 substrate by a direct reaction of milled Ga2O3 powders and NH3. The width of the nanobelts is in the range from 100 nm to 1 μm, and the ratio of thickness to width is about 110. The maximum length is up to several tens of micrometers. The clear lattice fringes in the high-resolution transmission electron microscopy images indicate the growth of good-quality hexagonal single-crystal GaN nanobelts. The Raman spectrum exhibits two additional peaks at 256 and 422 cm−1. The photoluminescence spectrum reveals a broad, strong blue emission band centered at 2.65 eV. The growth mechanism of the GaN nanobelts is briefly discussed.