Measurement Changes in Activation Energy, Hall Effect and Seebeck Effect of Lead Telluride Thin Films Prepared by Thermal Evaporation Technique with Different Annealing Temperatures

The main purpose of the work reported in this paper was to study the electrical properties in PbTe films of thickness 250 nm deposited on clean class substrates held at room temperature in a vacuum of 10 -5 mbar prepared by thermal evaporation technique and annealed at different temperatures. Electrical properties of the films were determined by electrical conductivity, Hall coefficient and seebeck coefficient measurements. The d.c conductivity of the as deposited and annealed films was determined within the range of 313-483 K. The activation energies (Ea) of the films increased as the films underwent annealing, The Hall and thermoelectric power measurements showed that the films conductivity is n-type for all films which indict that the majority of charge carriers are electrons, except film annealed at temperature equal to 423 K where the film exhibits p-type. The carrier concentration (nH) decreases with increasing Ta while Hall mobility (H) increases with increasing Ta. The seebeck coefficient and activation energy (ES) of the films with different Ta have been investigated.