Single-crystal SnO2 nanoshuttles: shape-controlled synthesis, perfect flexibility and high-performance field emission.

Vertically aligned single-crystal SnO2 nanoshuttle arrays with uniform morphology and a relatively high aspect ratio were synthesized by a simple hot-wall chemical vapor deposition (CVD) method. It was found that regulating the growth temperature gradient could change the shape of the SnO2 nanostructure from nanoshuttles to nanochisels and nanoneedles, and a self-catalyzing growth process was responsible for tunable morphologies of SnO2 nanostructures. The as-synthesized SnO2 nanoshuttles showed ultrahigh flexibility and strong toughness with a large elastic strain of [?] 6.2, which is much higher than reported for Si and ZnO nanowire as well as most crystalline metallic materials. The field emitter fabricated using SnO2 nanoshuttle arrays has a low turn-on electric field of around 0.6 V um [?] 1, and a high field emission current density of above 10 mA cm [?] 2, which is comparable with the highest emission current density of carbon nanotube and nanowire field emitters. [ABSTRACT FROM AUTHOR]