Abstract
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•Synthesis of ZnAlS alloy by solid state reaction method.•Amount Al atoms concentration was varied to modulate thermoelectric properties.•Structure was verified by XRD and Raman spectroscopy.•Thermoelectric properties enhanced by Al concentration.
In the present study, we have successfully controlled the structural and thermoelectric properties of ZnAlS nanoparticles alloy by varying the concentration of Al atoms (1, 2, 3 and 4 %). The samples under investigation were prepared by the solid state reaction method and were characterized using X-ray Diffraction (XRD), Raman spectroscopy measurements and Seebeck data. XRD data have confirmed the cubic phase of ZnS with specific planes 100), (111), (220), and (311). XRD data also verified that structure quality of prepared samples was found to be decreased as we increased the concentration of Al atoms up to 4 %. Raman data demonstrated two peaks at 285 and 348 cm−1 which are assigned as TO and LO modes of cubic ZnS respectively. Seebeck coefficient/thermomotive force and electrical conductivity values are increased to 153.5 μV/°C and 1011.11 S/µm respectively, when the concentration of Al atoms increased to 4 % and measurement temperature reached at 100 °C. The simultaneous enhancement in conductivity and Seebeck data suggested the formation of secondary phases when we increased the concentration of Al atoms because extra Al atoms are unattended by the ZnS structure therefore these atoms are involved in the formation of secondary phases.