Effect of Annealing on the AC Conductivity and the Dielectric Properties of In2Te3 Thin Films

M.A. Afifi, E. Abd El-Wahabb, A.E. Bekheet and H.E. Atyia Physics Department, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt

Full Text PDF

Received: April 26, 2000; revised version July 13, 2000

In2Te3 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 In2Te3 films as well as films annealed at temperatures ≤473K have crystalline structure. The ac conductivity σac(ω), the dielectric constant ε1 and the dielectric loss ε2 of In2Te3 films were studied in the temperature range 303-373K and in the frequency range 100Hz-100kHz. The ac conduction activation energy ΔEσ(ω) was found to be 0.065eV for the as-deposited films. The ac conductivity was found to obey the relation σac(ω)=Aωs, where s is the frequency exponent. The obtained temperature dependence of s is reasonably interpreted by quantum mechanical tunneling model. Both the dielectric constant ε1 and the dielectric loss ε2 increased with temperature and decreased with frequency in the investigated range. The frequency and temperature dependencies of σac(ω), ε1, and ε2 for the annealed samples have the same behavior as that for the as-deposited samples. However, values of σac(ω), ε1, and ε2 measured at any frequency and temperature increased with annealing temperature up to 473K. It was found also that ΔEσ(ω) decreased with annealing temperature.

DOI: 10.12693/APhysPolA.98.401 PACS numbers: 72.20.-i, 77.55.+f