Improving the Electrical Parameters of Se80Te20 Films by the Sn Substitution for Te and Thermal-Induced Effect

Films of Se80Te20-xSnx (where x = 6 at.%, 12 at.%, and 15 at.%) were prepared by thermal evaporation in a certain thickness of similar to 450 nm. Both the structural and electrical properties of as-prepared and annealed Se80Te20-xSnx films were studied. The annealing process was performed at 373 K, 393 K, and 413 K to cover the amorphous-crystalline region. Structural analyses show an improvement of film crystallinity with increasing both Sn content and annealing temperature. On the other hand, the electrical conductivity also shows significant enhancement with increasing Sn content and annealing temperature. The electrical results reveal that, at low temperature, conduction takes place through variable range hopping in localized states close to the Fermi level. Consequently, it has been shown in high temperature was explained by thermal charge carrier activation tunneling in the band tails of localized states. More structural and electrical parameters were evaluated for the Se80Te20-xSnx films to increase the understanding of the electronic properties of the Se-Te-Sn system.