Thermoelectrical Properties of ITO/Pt, In2O3/Pt and ITO/In2O3 Thermocouples Prepared with Magnetron Sputtering

ITO/Pt, In2O3/Pt and ITO/In2O3 thermocouples were prepared by the radio frequency (RF) magnetron sputtering method. The XRD results showed that all the annealed ITO and In2O3 films annealed at high temperature present a cubic structure. Scanning electron microscope results showed that the thickness of the ITO and In2O3 films could reach 1.25 µm and 1.21 µm, respectively. The ITO/Pt and In2O3/Pt thin film thermocouples could obtain an output voltage of 68.7 mV and 183.5 mV, respectively, under a 900 °C temperature difference, and at the same time, the Seebeck coefficient reached 76.1 µV/°C and 203.9 µV/°C, respectively. For the ITO/In2O3 thermocouple, the maximum value of the output voltage was 165.7 mV under a 1200 °C temperature difference, and the Seebeck coefficient was 138.1 µV/°C. Annealing under different atmosphere conditions under 1000 °C, including vacuum, air and nitrogen atmospheres, resulted in values of the Seebeck coefficient that were 138.2 µV/°C, 135.5 µV/°C and 115.7 µV/°C, respectively.