Selective growth of zigzagged and straight GaN nanowires by sublimation sandwich method and their photoluminescence property

Large-scale zigzagged and straight GaN nanowires have been grown on pre-treatment SiO2 substrate by sublimation sandwich method (SSM) without using any catalyst. The structural properties of these nanowires were investigated in detail. It is found that both zigzagged and straight GaN nanowires are single-crystalline wurtzite GaN growing along [0 0 0 1] direction, and vapor–solid (VS) mechanism should be responsible for the growth of these nanowires. In addition, photoluminescence spectra of these two kinds of nanowires exhibit different optical properties, which is maybe due to the difference in chemical composition condition of these zigzagged and straight GaN nanowires.