Effect of Annealing on the Thermoelectricity Properties of the WRe26-In(2)O(3) Thin Film Thermocouples

WRe26-In(2)O(3) (WRe26 (tungsten-26% rhenium) and In(2)O(3) thermoelectric materials) thin film thermocouples (TFTCs) have been fabricated based on magnetron sputtering technology, which can be used in temperature measurement. Many annealing processes were studied to promote the sensitivity of WRe26-In(2)O(3) TFTCs. The optimal annealing process of the thermocouple under this kind of RF magnetron sputtering method was proposed after analyzing the properties of In(2)O(3) films and the thermoelectric voltage of TFTCs at different annealing processes. The calibration results showed that the WRe26-In(2)O(3) TFTCs achieved a thermoelectric voltage of 123.6 mV at a temperature difference of 612.9 K, with a sensitivity of up to 201.6 µV/K. Also, TFTC kept a stable thermoelectric voltage output at 973 K for 20 min and at 773 K for two hours. In general, the WRe26-In(2)O(3) TFTCs developed in this work have great potential for practical applications. In future work, we will focus on the thermoelectric stability of TFTCs at higher temperatures.