Fabrication, characterization and hydrogen gas sensing performance of nanostructured V2O5 thin films prepared by plasma focus method

Abstract

Nanocrystalline V2O5 thin films were deposited on glass substrates at room temperature using a low energy (1.3 kJ) plasma focus device. The argon:oxygen gas mixture (in 7:3 ratio) was utilized as a working gas and metallic vanadium was used as the anode tip material. The V2O5 thin films were synthesized with different number of shots (10, 20 and 30 shots), at 0° angular position with respect to the anode axis and at same axial position from the tip of anode (10 cm). The structural properties and phase composition of the thin films were studied by means of X-ray diffraction (XRD) and Raman scattering analysis. The results obtained from scanning electron microscopy (SEM), and atomic force microscopy (AFM) analyzes revealed that the size of nanoparticles/agglomerates and surface roughness of V2O5 thin films strongly depend on number of shots. The variation in the gas response of the V2O5 thin films for 1000 ppm concentration of hydrogen gas at different operating temperatures (150–350 °C) revealed an optimal operating temperature of 275 °C. Moreover, among all the V2O5 thin films studied, the sample deposited with ten shots showed the maximum gas response to various H2 concentrations at optimal operating temperature.