Determination of Contact Resistivity by the Cox and Strack Method for Metal Contacts to Bulk Bismuth Antimony Telluride

Abstract

We successfully demonstrate the application of the Cox and Strack (CS) technique for contact resistivity measurement of metal contacts to bulk bismuth antimony telluride. The transmission line method (TLM), typically used for thin films, gives inconsistent contact resistivity results for bulk thermoelectric (TE) materials. Using TLM we observed a 10× variation in measured contact resistivity for the TE material thickness range of 300―1000 μm. In contrast, the CS method gives a <3% variation over the same substrate thickness range. We propose that this variability difference is related to the direction of current flow in the bulk TE materials.