Parallel ultrafine SiO 2 nanowires coated with amorphous SiO 2

The parallel ultrafine SiO2 nanowires coated with amorphous SiO2 have been synthesized by a thermal evaporation method. The samples have been systematically studied by X-ray powder diffraction, Raman spectroscopy, scanning electron microscope, high-resolution transmission electron microscopy, selective area electron diffraction, and photoluminescence. The results show that the synthesized nanowire consists of a composite structure of the amorphous shell and the nanometer-sized crystalline core which has a monoclinic structure. The diameter of the internal one-dimensional crystal structure is about 10 nm. Furthermore, the luminous performance of SiO2 nanowires coated with amorphous SiO2 reveals a stable and strong yellow-red emission band. The products might be suitable for optoelectronic semiconductor application.