Influence of Copper Doping on Structural, Morphological, Electrical Properties of WO3 Nanoparticles

In this work, Pure and Cu-doped WO3 nanoparticles have been synthesized using the wet chemical method. The effect of Cu-doping on the structural, morphological, electrical and dielectric properties of WO3 nanoparticles was investigated. XRD pattern described that Cu-doping without affecting the monoclinic structure of the samples and the few peaks corresponding to Cu, it conforms secondary phase. The presence of more distortion centers and interstitials in Cu-doped sample led to increasing the crystallite size. FESEM analysis has shown the morphology of doped and pure WO3 nanoparticles to be quasi-spherical. EDAX spectra confirmed the presence of W, O and Cu. The DC and AC conductivity have been measured at a temperature range from 303-403K in the frequency range of 42Hz-5MHz. The DC conductivity was found to increase with increasing Cu and indicates the semiconducting nature. The activation energy has also been observed to decrease with Cu doping. The DC conductivity of the present samples follows small polaron hopping. The frequency dependence of dielectric constant (�’), dielectric loss (tan δ) and AC conductivity of WO3 nanoparticles of different Cu doping concentration at different temperature was measured. Temperature variation of frequency exponents in 15 wt% Cu-doped WO3 suggests that AC conduction is attributed to be correlated barrier hopping.