Multiangular Branched ZnS Nanostructures with Needle-Shaped Tips: Potential Luminescent and Field-Emitter Nanomaterial

Abstract

A facile and effective route toward the synthesis of ZnS multiangular branched nanostructures with needle-shaped tips has been developed. An average width of the structurally and chemically uniform, single-crystalline, defect-free tips was found to be less than 10 nm. Cathodoluminescence from individual ZnS multiangular branched nanostructures was investigated at high spatial resolution on the nanometer scale. The size-dependent optical spectra exhibit sharp ultraviolet band gap emission and broad visible emission. Field-emission measurements show a relatively low turn-on field of ∼3.77 V/μm at a current density of 10 μA/cm2 and the highest field enhancement factor β of ∼2182 ever reported for 1D ZnS nanostructures. This was attributed to the specific sharp tips and high aspect ratios. These unique nanostructures are envisaged to be highly promising for novel optoelectronic and field-emitting devices.