Thermal correction method for accurate performance evaluation of micro-thermoelectric coolers

The micro-thermoelectric coolers (TECs) with enhanced cooling power density are indispensable for precisely controlling the temperature of optical modules. While the accurate characterization of cooling performance is of paramount importance, a particular difficulty lies in the precise measurement of cooling power for such miniaturized devices. The Harman method and impedance spectroscopy employed for industrial applications are incapable of measuring the cooling power and COP, while the reference sample method will cause significant deviations. Herein, a thermal correction method has been developed to precisely characterize the cooling performance of a micro-TEC. By calibrating the heat losses, the relationship between the input electrical power of the heater and the cooling power of a TEC can be established. It thereby allows the direct measurement of the temperature difference, cooling power, and coefficient of performance (COP) of a TEC at different operating currents. The variation of cooling power and temperature difference across the multiple tests is less than 2.3%, while the variation of cooling temperature difference is less than 1.1%, indicating the high stability and reproducibility of the method. Furthermore, this method has been extended beyond micro-TEC to the measurement of a conventional-size TEC, underscoring the versatility of this technique. Importantly, the accuracy of the characterization has been further verified by comparing the measured COP with the theoretical values. Our work establishes the thermal correction method as a viable technique for the accurate evaluation of the cooling performance of TECs.