Temperature dependence of electrical and thermal properties of Te_82.2Ge_13.22Si_4.58 glassy alloy

Thin film and bulk samples were prepared from synthesized amorphous Te_82.2Ge_13.22Si_4.58 chalcogenide glassy alloy by the thermal evaporation technique. X-ray analysis shows that both synthesized material and thin film forms have an amorphous nature. The electrical and thermal conductivities for the bulk sample were studied as a function of temperature in a range below T_g (T_g = 423 K). The obtained results for electrical conductivity are explained in accordance with the Mott and Davis model. The switching effects in amorphous films were also investigated. The switching phenomenon for this composition was of memory type. The mean value of the threshold voltage _th was found to increase linearly with increasing film thickness (98.9-250.1 nm), while it decreased exponentially with increasing temperature (below T_g). The results obtained are explained in accordance with the electrothermal model for the switching process.