core–shell nanowires with different shapes: Synthesis and field emission properties

Three different shapes of SiC/SiO2 core–shell nanowires were synthesized on Si substrates through a reaction between methane and silica using iron as catalyst. Analysis of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results indicated that catalyst morphology was the key factor for the formation of these three different products. The field emission properties of these three nanowires were investigated. Comparing the field emission results of these three nanowires, we can obtain a conclusion that a vertically well-aligned orientation to the substrate played a very significant role in improving the field emission properties when the emitters are up to a considerable number.