Interface Characterization of Cobalt Contacts on Bismuth Selenium Telluride for Thermoelectric Devices

Sputtered Co is investigated as a suitable contact metal for bulk , and the results are compared to sputtered Ni. The coefficient of thermal expansion of Co matches that of bulk used in our study, and the compatible interface favors the selection of Co as a contact metal. Significant Ni diffusion into was observed. In contrast, Co on shows significantly less diffusion, even at anneal temperatures as high as . is the preferred phase that is formed. First principles calculations for support the experimental observation.