Particle size-dependent electrical resistances of WO3 nanofibers

This work reports the fabrication steps and the particle size-dependent electrical resistances of WO₃ nanofibers produced by an electrospinning technique. The nanofibers are prepared by mixing ammonium metatungstate hydrate (AMH) in deionized water at various concentrations with polyvinyl alcohol (PVA). Such mixture is then electrospun onto platinum interdigitated electrodes, following by a hot pressing and calcination processes. It is found that lower precursor concentrations and lower calcination temperatures resulted in smaller WO₃ particles consisting in the nanofibers. Particle size-dependent electrical resistances are found in these nanofibers, and are believed to be related to the size of the space-charge layer in individual WO₃ particle. This study provides information about synthesis parameters used to control physical dimensions of the WO₃ particles and the magnitudes of the electrical resistances associated with the structures.