Determination of electrical contact resistivity in thermoelectric modules from module-level measurements

Thermoelectric modules (TEMs) are solid-state devices used for cooling, heating and power generation. An experimental apparatus was developed to characterize the performance of a TEM and heat sink assembly, where the TEM is operated in refrigeration mode. A numerical model was developed to simulate the experiments. Bulk and interfacial Ohmic heating, along with Peltier and Thomson effects were modeled with the inclusion of temperature-dependent bulk material properties, i.e., Seebeck coefficient, thermal conductivity and electrical conductivity. A novel, self-consistent characterization methodology was developed to obtain the electrical contact resistance of the TEM module based on the numerical simulations and the experiments. The electrical contact resistivity of the module tested was predicted to be approximately 1×10-9 Ω.m2. The predictions match with the electrical contact resistivity obtained based on the performance specifications (Tmax) of the TEM.