Investigation on thermoelectric properties of screen-printed La_1-xSr_xCrO₃-In₂O₃ thermocouples for high temperature sensing

La_1-xSr_xCrO₃-In₂O₃ thick film thermocouples were fabricated by screen-printing method for high temperature sensing and the effects of Sr²⁺ content were investigated systematically. All La_1-xSr_xCrO₃ thick films showed well crystallization with orthorhombic unit cell. Their average particle sizes showed the tendency of first increase then decrease gradually with the increase of Sr²⁺ content, and the maximum of average particle size was 1.76 μm. At the same time, the conductivities were improved with the increase of Sr²⁺ content. The thermoelectric properties of La_1-xSr_xCrO₃ depended on the Sr²⁺ content and the average Seebeck coefficients had an exponential decay tendency with the increase of Sr²⁺ content. For La_1-xSr_xCrO₃ (x = 0.1–0.4)-In₂O₃ thermocouples, excellent repeatability and stability were observed through multi-cycles and long-time usage testing at high temperature. The La_0.7Sr_0.3CrO₃-In₂O₃ thick film thermocouple with excellent thermal stability (drift rate: 0.81 °C/h) and reliability makes it become a promising candidate high sensitivity thermal sensor.