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Summery and conclusionsTin telluride is a IV-VI compound. It has a very interesting properties as narrow gap, high dielectric constant, high mobility, high density of charge carriers and has two maxima valance band. In addition, SnTe has been launched in many application such aIn this study SnTe was synthesized and deposited in thin film form utilizing thermal vacuum deposition technique. For best quality films, flash evaporation was applied in order to obtain high quality thin films of SnTe. Prior to the study of the physical In order to investigate the electrical properties of SnTe thin films, the DC resistivity, thermoelectric power, AC conductivity and the dielectric constants were considered. According to the DC resistivity measurements of thin films of SnTe, it has been fConsidering the dielectric properties for their importance particularly in the technical application, the AC conductivity, the dielectric constant, the dielectric loss and the loss tangent were investigated as a function of field frequency, temperature anFor the significant informations which can be extracted from the optical properties as the optical constants, dielectric constants, absorption coefficient plasma frequency, energy gap and type of transition, thin films of SnTe were optically investigated Following are the overall conclusions:-1- SnTe thin films have been synthesized and thermally vacuum evaporated using flash evaporation technique.2- From the X-ray study, and the TEM investigation the studied thin films were polycrystalline and have fcc structure with lattice constant a ? 6.3075?.3- According to the EDX analysis, the deposited thin films were stoichometric and no phase changes were detected after heat treatments of the films.4- Regarding the DC electrical resistivity of SnTe thin films, the films behave as a semimetal and metals.5- In respect of the thermoelectric power measurements the SnTe thin films have a semiconducting properties with type p of charge carriers.6- A transition from the extrinsic conduction at low temperature to an intrinsic conduction at high temperature was detected in SnTe thin films characteristics.7- SnTe thin films are characterized with a relatively high density of charge carriers in order of 1-5x1019cm-3 and high drift mobility ? 400 cm2 /V.sec.8- It is concluded that the AC conduction is governed by the small polaron hopping mechanism with hopping energy in the order of 0.24eV and relaxation jump time in order of 1-4x10-6sec.9- Form the optical investigation it has been concluded that the SnTe thin films are characterized by allowed direct transition with two values of optical energy gaps.10- In agreement with the band structure and the electrical properties the values of the optical energy gapes were found to be 0.18eV and 0.52eV.11- A quite good agreement between the obtained results and the reported results concerning the energies of the critical points using different techniques was found.
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