Effect of Annealing on the AC Conductivity and the Dielectric Properties of In$\text{}_{2}$Te$\text{}_{3}$ Thin Films

In$\text{}_{2}$Te$\text{}_{3}$ thin films were prepared by thermal evaporation technique. The composition of the films is checked by energy dispersive X-ray analysis. X-ray analysis showed that the as-deposited In$\text{}_{2}$Te$\text{}_{3}$ films as well as films annealed at temperatures ≤473K have crystalline structure. The ac conductivity σ$\text{}_{ac}$(ω), the dielectric constant ε$\text{}_{1}$ and the dielectric loss ε$\text{}_{2}$ of In$\text{}_{2}$Te$\text{}_{3}$ films were studied in the temperature range 303-373K and in the frequency range 100Hz-100kHz. The ac conduction activation energy ΔE$\text{}_{σ}$(ω) was found to be 0.065eV for the as-deposited films. The ac conductivity was found to obey the relation σ$\text{}_{ac}$(ω)=Aω$\text{}^{s}$, where s is the frequency exponent. The obtained temperature dependence of s is reasonably interpreted by quantum mechanical tunneling model. Both the dielectric constant ε$\text{}_{1}$ and the dielectric loss ε$\text{}_{2}$ increased with temperature and decreased with frequency in the investigated range. The frequency and temperature dependencies of σ$\text{}_{ac}$(ω), ε$\text{}_{1}$, and ε$\text{}_{2}$ for the annealed samples have the same behavior as that for the as-deposited samples. However, values of σ$\text{}_{ac}$(ω), ε$\text{}_{1}$, and ε$\text{}_{2}$ measured at any frequency and temperature increased with annealing temperature up to 473K. It was found also that ΔE$\text{}_{σ}$(ω) decreased with annealing temperature.