Improvement of structural, morphological and thermoelectric power factor of thermally evaporated Sr doped SnTe film

In this study, we have investigated the effect of strontium (Sr) doping on the thermoelectric properties of thin films made of tin telluride (SnTe). The preparation of Sn1-xSrxTe (x = 0, 0.1, 0.2, 0.3, 0.4) films using a straightforward thermal evaporation method and subjected them to post-annealing at 773 K. The surface morphology and crystal structure of the films have been examined by using SEM and XRD, respectively. Our findings indicate that the Seebeck coefficient value increased from 39 to 68 μV/K as the Sr doping concentration increased. This enhancement has been attributed to the energy filtering effect resulting from charge carrier dislocation. However, the electrical conductivity value decreased due to an increase in defect density. The maximum enhancement of the power factor has been observed for x = 0.3, where the value reached 38.9 μWcm−1K−2, which is greater than the pristine sample. Our results conclude that Sr0.3 doping in Sn0.7Te is a valuable addition for thermoelectric applications at room temperature. Additionally, the use of the simple thermal evaporation method for film preparation highlights its potential for large-scale applications.