Synthesis of SiO_2 Nanowires and CdS/SiO_2 Composite Nanowires and Investigation of Their Electron Field Emission Properties

摘要

A thermal evaporation method was used to obtain SiO_2 and CdS/SiO_2 nanowires by heating Si substrates coated with a gold thin film in a quartz tube furnace. During growth, pure CdS powder was placed at the heating zone in the furnace, serving as the CdS source for the CdS/SiO_2 composite nanowires. It was found that both non-porous and porous Si substrates served as the Si source for the growth of SiO_2 nanowires and the CdS/SiO_2 composite nanowires. It was also found that the effect of the temperature gradient in the reaction chamber plays an important role in the density distribution of different nanowires (SiO_2 or CdS/SiO_2 nanowires). The electron field emission properties of these nanowires were investigated using an electron field emission microscope equipped with a Faraday cup.