ABSTRACT
This chapter reviews the main technique issue in Bi2Te3-based thermoelectric (TE) devices, i.e., the contact design, which involves the choice of metal interconnect and joint method. TE devices share a very simple configuration with metal interconnects, serially joining the p-type and n-type legs between two ceramic substrates through diffusive bonding or soldering. Contact resistance involves all the contributions from the interfaces, thin layer between electrodes, and TE elements. In the case of soldering bond, the contact resistance mainly comes from the interface between the metallization layer and TE elements. Besides the roughness of the TE elements surface, the careful surface cleaning before sputtering or plating the metallization layer is another important factor to determine the interface performance, especially the contact resistivity. For the real power generation, the bonding strength between the nickel layer and the TE elements becomes even more critical than the contact resistance.
