We have published this month a new article reporting the potential of impedance spectroscopy as a method to measure thermoelectric properties. Impedance spectroscopy has proved to be a very useful and reliable technique in a lot of fields and powerful equipments are available in the market and in many research centres. We have proved in this new article that impednce can also become very useful in the field of thermoelectrics since it can provide the usually required thermoelectric parameters.
In a first approach, by measuring a thermoelectric element using Ag paint as contacts, all the thermal properties (thermal conductivity, thermal diffusivity and specific heat) can be measured if the Seebeck coefficient is known. Secondly, we describe that by attaching contacts of known thermal conductivity, such as the ceramics in the thermoelectric modules, a complete characterisation can be achieved, i. e., the Seebeck coefficient, the electrical conductivity and the mentioned thermal properties can potentially be extracted.
In addition, new parameters such as thermoelectric capacitance and thermoelectric resistances can be extracted which give information about the physics of the device. All these results are available in our article in the Journal of Applied Physics and in the seminar I gave at Purdue University few months ago which has been recorded and published at the Nanohub website.