Controlled growth of SiC flexible field emitters with clear and sharp tips†
With respect to the effect of local field enhancement, fabrication of nanostructures with clear and sharp tips is critically important for the exploration of field emitters with high performances. In the present work, aimed at the exploration of the flexible SiC field emitters with excellent properties, we report the controlled growth of quasialigned SiC nanoarrays with sharp tips via catalyst assisted pyrolysis of polymeric precursors on the carbon fabric substrates by tailoring the cooling rates. The resultant products are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). It is found that the growth of SiC quasialigned nanoneedle arrays with unique sharp tips could be achieved by reducing the cooling rates over the high-temperature pyrolysis process, enabling the capability for the controlled growth of SiC flexible field emitters on carbon fabric. The cooling rates are optimized, which suggests that 17.5 °C min−1 is low enough to favor the growth of SiC nanowires with clear and sharp tips. The growth of the quasialigned SiC nanoarrays with sharp tips based on the typical VLS mechanism has been proposed. The FE property measurements suggest that the electron emission could be remarkably enhanced by tailoring the growth of SiC nanowires with clear and sharp tips.