Effect of Microwave-assisted Post-treatment on the Structural, Electrical, and Thermoelectric Properties of Flexible Sb2Te3 Films Prepared by DC Magnetron Sputtering
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Abstract
Flexible Antimony telluride (Sb2Te3) thin films were coated on a polyimide substrate by DC magnetron sputtering using an alloy 99.9% Sb2Te3 target. The effects of microwaveassisted post-treatment at various temperatures 473, 523, 573, and 623 K for 1 min under N2 atmosphere on the [Sb]:[Te] ratio, structural, surface morphology, electrical, and thermoelectric properties were studied. The [Sb]:[Te] ratio of flexible Sb2Te3 film was determined by energy dispersive spectrometry (EDS). EDS analysis revealed that the Te ratio was slightly decreased when heat treatment increased. The crystal structure and surface morphology of flexible films were characterized by x-ray diffraction (XRD) and a field emission scanning electron microscope (FE-SEM), respectively. All samples confirmed the polycrystalline Sb2Te3 with a hexagonal structure. The crystallinity is heightened by the heat treatment process. Electrical transport properties were measured by Hall Effect measurements. The Seebeck coefficient and electrical conductivity were simultaneously measured at room temperature by a DC four-terminal method (Seebeck Coefficient/Electrical Resistance Measurement System). The results indicated that the microwave heat treatment can enhance the electrical conductivity and Seebeck coefficient of the flexible films leading to reaching a maximum power factor of 1.71 mW/K2m, which is annealed at 523 K.
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