The dielectric studies on sol–gel routed molybdenum oxide thin film

Abstract

The influence of temperature on the dielectric properties of sol-gel routed spin-coated molybdenum trioxide (MoO[Formula: see text] thin film has been investigated. Prepared films were annealed at temperatures 250[Formula: see text]C, 350[Formula: see text]C and 400[Formula: see text]C. The phase transformation from amorphous to [Formula: see text]-orthorhombic phase with preferential orientation (0 2 2) has been found by XRD for the film annealed above 250[Formula: see text]C. The vibration modes of [Formula: see text]-orthorhombic MoO3 have been examined by Raman spectrum. The predominant Raman’s band of [Formula: see text]-orthorhombic MoO3 thin film has been found at the frequency range 1000–600[Formula: see text]cm[Formula: see text]. Using the UV–Vis spectrum, the band gap of the film is found to be 3.3–3.8[Formula: see text]eV. The surface morphology of the MoO3 films has been examined by scanning electron microscope. The AC conductivity measurement of the MoO3 film has been carried out in the frequency range 10–106 Hz. The frequency dependence of the impedance has been plotted in the complex plane. The variation of the capacitance and dielectric constant of MoO3 film with respect to temperature and frequency has been analyzed. Tunability of capacitance and figure of merit of the film are also determined.