Mapping of Work Function in Self-Assembled V2O5 Nanonet Structures

We presented a mapping the work function of the vanadium pentoxide (V2O5) nanonet structures by scanning Kelvin probe microscopy (SKPM). In this measurement, the V2O5 nanonet was self-assembled via dropping the solution of V2O5 nanowires (NWs) onto the SiO2 substrate and drying the solvent, resulting in the networks of V2O5 NWs. We found that the SKPM signal as a surface potential of V2O5 nanonet is attributed to the contact potential difference (CPD) between the work functions of the metal tip and the V2O5 nanonet. We generated the histograms of the CPD signals obtained from the SKPM mapping of the V2O5 nanonet as well as the highly ordered pyrolytic graphite (HOPG) which is used as a reference for the calibration of the SKPM tip. By using the histogram peaks of the CPD signals, we successfully estimated the work function of similar to 5.1 eV for the V2O5 nanonet structures. This work provides a possibility of a nanometer-scale imaging of the work function of the various nanostructures and helps to understand the electrical characteristics of the future electronic devices.