Abstract
Bismuth telluride based compounds have been considered as promising candidates for thin-film thermoelectric (TE) devices due to their superior thermoelectric figure-of-merit at room temperature regime. Thermoelectrics/metal electrode junctions usually cause extra resistance to electron flow and heat flux in a typical TE module, and hence degrade the efficiency of TE devices. Such electrical/thermal contact resistance may become a performance killer, especially for thin-film TE devices. Thus, a methodology of evaluating the electrical/thermal contact resistance of TE/metal interfaces becomes essential. In this study the electrical and thermal contact resistances of Bi-Sb-Te thin film/metal were measured using the transmission-line-model (TLM) and the transient 3ω techniques, respectively. In this study, the results show that the electrical contact resistivities of Bi-Sb-Te/metals are in the order of 10-5 ohm-cm2 and the thermal contact resistances of the Bi-Sb-Te/metals are in the order of 10-8 m2K/W, respectively. The effects of Fermi energy of Bi-Sb-Te compounds and the work function of metals on the electrical and thermal contact resistances of Bi-Sb-Te film/metal interfaces are investigated.