Precise characterization of Peltier heat at the heterointerface based on thermography

Abstract

With the increasingly widespread application of thermoelectric cooling technology, the demand for precise characterization of the Peltier effect at material heterointerfaces is growing rapidly. It can help us develop thermoelectric materials and study the charge–phonon interaction and energy conversion laws at heterointerfaces. However, direct measurement results for Peltier heat are scarce, mainly because existing electrical or thermal imaging measurement methods find it difficult to accurately measure the heat flow through samples. Furthermore, the Peltier effect in thermoelectric elements occurs simultaneously with several heat generation and heat transfer processes, adding further complexity to the measurement. In this study, we proposed a Peltier effect characterization method based on infrared thermography and accurately characterized the Peltier heat of the Bi2Te3 and Mg3(Sb,Bi)2 PN junction heterointerface using a steady-state and direct experimental system. The measurement results can form a good mutual verification with the Kelvin relationship and the Onsager reciprocal relationship. Compared with other existing measurement techniques, our method quantitatively analyzes the value of radiation heat, eliminates its influence by bidirectional current method, and can directly obtain the value of heat flux. This measurement method can achieve a temperature resolution of 50 mK and a heat flux resolution of 0.1 mW, which not only presents an effective means of accurately measuring small heat flux but also provides guidance for the development of thermoelectric theory and thermoelectric devices.