Direct synthesis of novel SiC@Al2O3 core-shell epitaxial nanowires and field emission characteristics

Abstract

SiC@Al₂O₃ core-shell epitaxial nanowires have been synthesized via one-step process by simply heating evaporating Al source and C source on silicon substrate. Energy dispersive X-ray spectroscopy and transmission electron microscopy analysis of as-fabricated samples indicate that the core-shell nanowires consist of single-crystalline β-SiC core and thin cubic γ-Al₂O₃ shell. Epitaxial relationship is also observed between SiC core and Al₂O₃ shell. The corresponding growth model is proposed to describe the growth process of the core-shell epitaxial nanowires. Moreover, field emission measurement reveals the core-shell epitaxial nanowires have the excellent field emission property with low threshold electric field of 13.8 V μm⁻¹.