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 100nm to 1μm, 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 422cm−1. The photoluminescence spectrum reveals a broad, strong blue emission band centered at 2.65eV. The growth mechanism of the GaN nanobelts is briefly discussed.