Study of the thermal behaviour of PN thermoelectric couples by laser probe interferometric measurement

The purpose of the present paper is to provide experimental data related to the temperature distribution within thermoelectric devices (TE). Moreover our aim is to get this knowledge for a dynamic temperature response of the device. We propose a non-contact optical measuring method, based upon very high-resolution interferometry, to map temperature effects upon the surface of running thermoelectric devices. The Peltier sources within the device generate thermal waves associated to heat transport. These waves interfere when AC current is driven through the device. The interferences are clearly observed in our measurements, showing how heat flows from different sources and merge. The measuring method can be used to check material properties which in turns allows to optimize contact design.