Fabrication of highly oriented 4H-SiC gourd-shaped nanowire arrays and their field emission properties

Abstract

The growth of highly oriented one-dimensional (1D) nanoarrays is critically important and highly desired, since it is one of the fundamental issues to push forward their applications in field emitters. In the current work, we reported the large-scale fabrication of highly oriented 4H-SiC gourd-shaped nanowire arrays with numerous sharp knots around the wire surface, which could be an ideal structural configuration for the exploration of emitters. The nanoarrays were prepared via an electrochemical anodic oxidation process assisted by pulsed voltage at room temperature (RT) and under atmospheric pressure. The formation of the gourd-shaped nanowires was mainly ascribed to the applied pulsed voltage, which caused the etching reaction, happened periodically and made the fluctuation of the diameters. Their measured field emission (FE) characteristics disclosed that the gourd-shaped SiC nanowire arrays had a low turn-on field of 0.95 V μm⁻¹, implying their good FE performances. The current emission fluctuations at RT and 200 °C are measured to be ∼±2.1 and ±2.8%, respectively, suggesting that they are robust to be serviced at high temperatures.