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

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 ( ε ′), loss tangent (tan δ ), and the ac electrical conductivity ( σ ac ) values are considerably sensitive to the frequency and temperature. The variations in ε ′, ε ″ and tan δ characteristics confirm the interfacial polarization. The values of C and ε ′ decrease with frequency, while σ ac 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.