Direct Growth of Au-Ga2O3 Core-Shell Nanowires and Their Field Emission Properties

Abstract

A simple, direct synthesis method for the growth of Au-Ga2O3 core-shell nanowires was reported in the work. The uneven concentration of precursor in Au catalyst in the vapor-liquid-solid process was proposed to induce a different growth rate at the interface between substrate and catalyst. The as-synthesized nanostructures were investigated by the use of transmission electron microscope. The existence of ~10 nm Ga3O layer at the surface of Au tip was verified by high angle annular dark field images. The small electron affinity of the thin layer Ga3O results in a remarkably high field enhancement factor of ~1200, and a lower turn-on field of ~4.7 V um-1 in the field emission measurement. This simple approach and outstanding field emission performance promises future applications of core-shell nanowires in nanoelectronics and vacuum electronic.