THE ROLE OF DIFFUSION IN THE DESTRUCTION OF CONTACTS IN TETRAMITE THERMOELECTRIC ELEMENTS

To study the thermocouples under conditions close to the working ones, the micromodule was annealed at 170 ° C for 1000 hours. It was found that, after annealing for more than 40 hours, disruptions of the contact zone of the n- type are observed, which leads to a complete rupture of the contacts of the micromodules. Our results showed that during annealing the SnSb takes place in the unprotected side surface of the thermoelement and contacts the cleavage planes along which the tin can diffuse into the volume of the thermoelement. In contrast, p-type pins were not destroyed by solder. The difference in the effect of the solder on the n- and p-type thermoelements was explained within the framework of the density functional theory (DFT). Simulation of the diffusion processes in Bi₂Te₃ and Sb₂Te₃ allowed us to expand our understanding of the process of soldering thermoelements.

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