Synthesis and optical properties of mullite (Al{sub}5.65Si{sub}0.35O{sub}9.175) nanowires

摘要

large quantities of mullite nanowires were synthesized on mica substrates. The nanowires were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and photoluminescence (PL) spectroscopy. The results indicate that the nanowire composition is Al{sub}5.65Si{sub}0.35O{sub}9.175, which fits the general mullite formula of Al{sub}(4+2x)Si{sub}(2-2x)O{sub}(10-x). The nanowires have a diameter range of 50-100 nm and lengths of several micrometers. Aligned nanowires can also been observed at the substrate edge. Raman microscopy indicated a change in the substrate surface occurred following the formation of nanowires. The nanowires have strong photoluminescence (PL) emission bands at 310, 397, 452 and 468 nm and the oxygen-related defect in the nanowires were supposed to be responsible for these emissions.