Preparation and Photoluminescence Properties of Tadpole-Like Amorphous Silica Nanowires

Abstract

Tadpole-like microstructures which consisted of silica nanowires have been synthesized on Si wafers at 950°C by using tin droplets as catalyst. Each tin droplet can simultaneously catalyzes the growth of many silica nanowires of each tadpole-like microstructure and can simultaneously catalyzes the growth of even two tadpole-like microstructures, which is quite different from the conventional vapor-liquid-solid process. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses show that the tadpole-like microstructures with diameters of 5 μm and lengths of up to 50-100 μm. The amorphous silica nanowires with a composition close to that of SiO2have diameters of 100–200 nm. The PL spectra of the SiO2nanowires shows a strong emission peak centered at 390 nm (3.18 eV), while two weak PL peaks at 323 nm (3.84 eV), and 455 nm (2.73 eV) can also be observed. The growth mechanism of the tadpole-like microstructures was also investigated.