Selective synthesis of SiO 2 NWs on Si substrate and their adjustable photoluminescence

Abstract

Amorphous SiO 2 nanowires with diameters of 20–200 nm and lengths of several micrometers were selectively grown，at 1100 °C under ambient pressure，on the ultra-thin Au film coated silicon wafers，which were characterized by scanning electron microscope, Fourier transform infrared spectroscope, and high resolution transmission electron microscope. Using X-ray energy dispersion spectroscope equipped on the high resolution transmission electron microscope, the investigation was carried out on the micro-region chemical composition of the as-grown amorphous SiO 2 nanowire. The growth mechanism has been discussed, and it has been believed to be extended vapor-liquid-solid process. The SiO 2 layer, as the result indicates, can prevent the formation of Si–Au alloy from Si–Au interface. This work also discusses the photoluminescence emission from SiO x centers at room temperature, it is found that by changing the oxygen, the photoluminescence intensity can be adjusted.