Growth and Field Emission of Single‐Crystalline Hafnium Carbide Nanowires

Abstract

<100>‐oriented hafnium carbide (HfC) nanowires are synthesized on the graphite substrate by chemical vapor deposition. The dependence of temperature, HfCl 4 content, and flow rate of CH 4 gas on the morphology of nanowires is investigated herein. The results indicate that the HfC nanowire often kinks to another growth direction at a high HfCl 4 content or a low temperature due to the destabilization of the catalyst droplet induced by either a faster growth rate or slower thermal activation. Reduced nanowire density and length are observed at the sample synthesized at a lower CH 4 flow rate. Based on the experimental results, high‐crystallinity nanowires with high aspect ratios and high densities are prepared at a lower HfCl 4 content, higher temperature, and high CH 4 flow rate. The field‐emission properties of a single HfC nanowire are also characterized by assembling a single HfC nanowire emitter. An extremely high field enhancement factor of 5.57 × 10 6 m −1 is obtained herein.