E NH A NCE M E NT O F T H E RMO E L E C T RI C PROPERTIES INDUCED BY CO IN ZnO
Keywords:
Synthesis, Zinc cobalt oxide, characterization, thermoelectric material, Thermoelectric propertiesAbstract
ZnO-based thermoelectric material shows high Seebeck coefficient, low electrical resistivity and low thermal conductivity. ZnO doped with Co can increase thermoelectricproperties. Zn1-xCoxO (x = 0.1, 0.2, 0.3) material were synthesized through solid state reaction (SSR) method. The powder precursor of ZnO and Co3O4 were mixed by ball milling in deionized water for 2 h, calcined at 1073 K and sintered at 1423 K for 5 h. The crystal structure was analyzed by X-Ray Diffraction (XRD) technique. The microstructure was observed by scanning electron microscopy (SEM). The Seebeck coefficient and electrical resistivity were measured by steady state method. This study found that the XRDpatterns of Zn0.9Co0.1O, Zn0.8Co0.2O and Zn0.7Co0.3O phase which matched of PDF#00-061-0685 indicating a hexagonal structure space group of P63mc (186). The SEM results revealed that the grain size of materials arrangement changed after sintering. The thermoelectric properties of Zn1-xCoxO (x = 0.1, 0.2, 0.3) had a Seebeck coefficient at amaximum value of -2442 μV/K condition of Zn0.8Co0.2O which was able to enhance aSeebeck coefficient value of - 474 μV/K of ZnO and electrical resistivity value of 57.02 Ω∙mwhich was enhanced from 5.72 Ω∙m at 473 K condition of Zn0.7Co0.3O comparing to ZnO.The powder factor was enhanced in all doping. It was confirmed that the samples weren-type thermoelectric materials which was in a semiconductor group.
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