Abstract
This work presents some electrical properties based on the impedance measurements as well as the dielectric constants on thermal evaporated Sb2O4 thin films additional to structural, opto-thermal and optical investigations which are reported previously by Ouni et al. in Journal of Non-Crystalline Solids (vol. 356 (2010) 1294-1299). The electrical conductivity and dielectric properties of Sb2O4 thin film were indeed studied using impedance spectroscopy technique in the frequency range 5 Hz-13 MHz at various temperatures (325-450 degrees C). The complex impedance diagram at different temperatures showed a single semicircle, implying that the response originated from a single capacitive element corresponding to the grains. AC and DC conductivities were studied to explore the mechanisms of conduction. It can be seen from the experimental data that the AC conductivity in thin films of Sb2O4 is proportional to omega(s) (s< 1), the value of s is to be temperature-dependent, which has a tendency to decrease in temperature. The temperature dependence of both AC conductivity and the parameter s is reasonably well interpreted by the correlated barrier hopping (CBH) model. Values of dielectric constants epsilon(1) and epsilon(2) were found to decrease with frequency and increase with temperature. Activation energy values deduced from both DC conductivity and relaxation frequency are of the order of E-a similar to 0.7 eV. The analysis of the parameters leads to the barrier height W-m value which is in agreement with that proposed by the theory of hopping of charge carriers over the potential barrier between the defect states in the band tail as suggested by Elliott. (C) 2013 Elsevier B.V. All rights reserved.