Abstract
Thin films of calcium cobalt oxide and zinc aluminium oxide were prepared onto ceramic substrates by a bipolar pulsed-dc magnetron sputtering system using a Ca3Co4O9 target and a ZnAlO target, respectively, under an argon atmosphere. Energy dispersive spectroscopy analysis revealed that the as-deposited films from the Ca3Co4O9 target comprised Ca, Co, O elements, while those from the ZnAlO target contained Zn, Al, O elements. Cross-sectional view estimation by the scanning electron microscope indicated that the as-deposited Ca-Co-O (CCO) and Zn-Al-O (ZAO) films had the thickness of 0.55 μm and 0.58 μm, respectively. X-ray diffraction analysis showed that the CCO thin film was grown in amorphous phase while the ZAO thin film exhibited hexagonal structure. From measurement of the properties, the p-CCO and n-ZAO films were found to exhibit the power factor of 0.13 and 14.39 μW/m K2, respectively. A thermoelectric module made from three pairs of the p-n thin film stripes provided the open circuit voltage and short circuit current up to 55.6 mV and 0.04 μA for a temperature difference of 101.40 K, respectively.