Structural and electric response of ITO/In2O3 transparent thin film thermocouples derived from RF sputtering at room temperature

Transparent thin film thermocouples have unique characteristics that it can be applied when permit minimal optical interference at in-situ temperature measurement. ITO/In2O3 thin film thermocouples were prepared on fused quartz glasses at room temperature by RF magnetron sputtering. For contrast, ITO thin films post-annealed at different temperatures were investigated accordingly. All films showed good conductivities, smooth surface morphology and high transmission, indicating negligible affection of the post-annealing temperature. The as-deposited ITO film has a Seebeck coefficient of 84.4 µV ºC−1. The thermoelectric voltage of 13.6 mV and significantly lower drift rate of 2.39 °C h−1 were obtained at 190 °C for ITO/In2O3 thin film thermocouples without any heat treatment. This makes the ITO/In2O3 transparent thin film thermocouples great potential as a promising temperature sensor.