EFFECT OF ANNEALING ON THE ELECTRICAL-PROPERTIES OF IN2SE3 THIN-FILMS

Thin film samples of In2Se3 were prepared from synthesized polycrystal line In2Se3 by a thermal evaporation technique. X-ray analysis show th at the synthesized material has alpha-phase structure, while the as-de posited films have an amorphous structure. The films have beta-phase s tructure after annealing at temperature greater than or equal to 523 K . The conduction activation energy (E(sigma)) of the as-deposited samp les, as obtained from the temperature dependence of the electrical con ductivity, is 0.391 eV. The obtained value of E(sigma) was explained a ccording to a previously postulated band structure of the investigated material. The electrical conductivity of the investigated samples beh aves differently with time after annealing at different elevated tempe ratures. On one hand, E(sigma) decreased for samples after annealing a t 423 and 473 K to 0.313 and 0.262 eV respectively; this may be due to the increase of the degree of ordering in the investigated compound w ith annealing. On the other hand, E(sigma) increased for samples after annealing at 523 K to 0.787 eV; this is due to its crystallization to the beta-phase, as confirmed by its X-ray diffraction pattern.