Synthesis and field emission properties of large-area arrays of tungsten oxide pencil-like nanostructure

摘要

Recent studies have shown that tungsten oxide nanomaterials such as nanowires and nanorods have very good field electron emission property [1–7]. In an early work, we have reported findings on very low field electron emission from tungsten oxide nanotip arrays grown by a two-step physical evaporation deposition process [1]. In this study, we demonstrate that large-area W18O49 pencil-like nanostructure arrays can be grown on silicon substrate by multi-step thermal evaporation process. Figure 1 shows a side view scanning electron micrograph of a typical W18O49 pencil-like nanostructure arrays (a) and the enlarged SEM image (b) of a nanotip, as well as their typical SAEDS spectrum (c) and typical XRD spectrum (d). The spacing of nanotip-to-nanotip between neighboring pencil-like nanostructures may be increased by adjusting growth temperature.