Temperature-dependent AC conductivity and dielectric and impedance properties of ternary In–Te–Se nanocomposite thin films

Abstract

The temperature- and frequency-dependent AC conductivity and dielectric and impedance properties of thermally evaporated ternary In–Te–Se nanocomposite thin films were measured in the temperature range from 100 to 300 K with the frequency range of 20 kHz–2 MHz. The measured dielectric constant (e′), loss tangent (tanδ), and the ac electrical conductivity (σac) values are considerably sensitive to the frequency and temperature. The variations in e′, e″ and tanδ characteristics confirm the interfacial polarization. The values of C and e′ decrease with frequency, while σac increases with both temperature and frequency. The estimated activation energy is found to decrease with increase in temperature. Further, the frequency dependence real (Z′) and imaginary parts (Z″) of the impedance spectra of the sample depend on the dielectric relaxation process. The Nyquist plot shows that the radius of the semicircular arc decreases with temperature and reveals a temperature-dependent relaxation process. The mechanism responsible for thermally assisted AC conduction can be due to the electronic hopping of charge carriers.