Physicochemical properties of sprayed V2O5 thin films: Effect of substrate temperature

• V2O5 thin films have been successfully deposited using chemical spray pyrolysis deposition method.
• The obtained results indicate that physicochemical properties of sprayed V2O5 thin films strongly depend on the substrate temperature.
• We expect that findings of the present work are best suitable for gas sensor application.

Polycrystalline vanadium pentoxide (V2O5) thin films have been successfully deposited onto preheated glass substrates via chemical spray pyrolysis deposition method at various substrate temperatures from 350 to 500 °C. The thermal decomposition behavior of vanadium trichloride (VCl3) powder has been studied using thermogravimetric–differential thermal analysis (TG–DTA). The effect of substrate temperature on the structural, morphological, optical and electrical properties has been investigated. XRD analysis showed that the films are polycrystalline with an orthorhombic crystal structure. SEM study showed the formation of rod like morphology of varying length from 0.8 to 1 μm and diameter from 230 to 300 nm. AFM study showed that the grain size varies from 134 to 304 nm. The optical results revealed that band gap energy decreases from 2.53 to 2.35 eV for direct allowed transition. The dielectric properties revealed that the dielectric constant (ϵ′) and dielectric loss tangent (tan δ) decreases whereas AC conductivity increases with increase in frequency of applied electric field. DC resistivity measurement results showed the semiconducting behavior of the V2O5 thin films.