Electrical characterization and Raman spectroscopy of individual vanadium pentoxide nanowire

We measured I–V characteristics, electrical resistance, and Raman spectra in the temperature range from room temperature to above 600 K to obtain nanodevices. Measurements were taken on a single V₂O₅ nanowire deposited on a Si template, where two- and four-point metallic contacts were previously made using e-beam lithography. In both two- and four-point probe measurements, the I–V curves were clearly linear and symmetrical with respect to both axes. Drastic reduction in electrical resistance and deviation from single valued activation energy with increasing temperature indicated phase transitions taking place in the nanowire. From temperature-dependent HR-Micro Raman measurements, reductions from V₂O₅ to VO₂/V₂O₃ phases took place at a temperature as low as 500 K, when electrons were injected to the nanowire through electrical contacts.