Effect of fluorine doping on the structural and gas sensing property of V2O5 thin films

Abstract

Pristine and fluorine doped vanadium pentoxide (V2O5) thin films are prepared by spray pyrolysis technique at different molar, dopant concentrations at a substrate temperature of 450 ˚C. The structural, optical, morphological, electrical and ethanol sensor studies are then carried out for these films. The band gap of the prepared host film at 0.03 M concentration has a lowest value of 2.43 eV and the 3 % of F doped V2O5 thin film has a lowest value of 2.39 eV. Morphological studies reveal that the film prepared at 0.03 M and 3 % doped films have good crystallinity. The electrical studies like I-V and Hall measurement on the host film has a conductivity of 245 Ω−1 m−1 and the carrier concentration of 4.74 × 1018 cm−3 where as for the doped film they are 253 Ω−1 m−1 and 7.25 × 1018 cm−3 respectively. Ethanol sensing property of these doped and un-doped V2O5 thin films are then studied. It is observed that F doped V2O5 thin films have higher sensitivity compared to the pure V2O5 thin films.