Measuring the local electrical properties of individual vanadium-pentoxide nanowires by using electrostatic force microscopy

A nanoscale investigation of the local electrical properties of individual vanadium-pentoxide (V2O5) nanowires (NWs) deposited on a SiO2/p+ Si substrate was carried out by using electrostatic force microscopy (EFM) in ambient conditions. We found that the EFM phase shift as an electrostatic response of V2O5 NWs to the biased-tip decreases with the lift height due to the electrostatic force gradient. We also observed that the EFM phase shift of V2O5 NWs shows the quadratic voltage dependence for a biased-tip with a fixed lift height. Furthermore, it is observed that the crossed junctions or bundles of the NWs compared to the single NWs showed higher electrostatic response, resulting in a large phase shift in the EFM measurements. These results suggest that the local electrical properties of V2O5 NW surface can be characterized in the nanoscale range by using EFM.