Influence of hydrogen incorporation on conductivity and work function of VO nanowires

We report improved conductance by reducing the work function via incorporation of hydrogen into VO 2 nanowires. The VO 2 nanowires were prepared using the chemical vapor deposition method with V 2 O 5 powder on silicon substrates at 850 °C. Hydrogenation was carried out using the high-pressure hydrogenation method. Raman spectroscopy confirmed that the incorporated hydrogen atoms resulted in a change in the lattice constant of the VO 2 nanowires (NWs). To quantitatively measure the work function of the nanowires, Kelvin probe force microscopy (KPFM) was employed at ambient conditions. We found that the work function decreased with increasing H 2 pressure, which also resulted in increased conductance. This is associated with hydrogen diffused into the VO 2 that acts as a donor to elevate the Fermi level, which was also confirmed by KPFM. From these results, tuning of the reversible electrical properties of VO 2 NWs, including the conductance and work function, can be achieved by incorporating hydrogen at relatively moderate temperatures. Effect of non-catalytic hydrogenation on the work function and charge transport properties of VO 2 nanowires (NWs) was investigated.