Investigation of Contact Resistance in the Structure of Thermoelements

The importance of contact resistance in the structure of thermoelements for the efficiency of thermoelectric devices is substantiated. A technique and a measurement complex were developed for determining the specific contact resistance at the level of 10
^-8
-10
^-10
Ohm*m
²
. When measuring the voltage drop across the structures under study, a four-wire circuit was used, which makes it possible to avoid errors determined by the resistance of the lead wires. The measuring error of the developed technique is not more than 5%. The transition contact resistance of thin-film Ni contact to samples of thermoelectric material Bi2Te2.8Se0.2 (0.14 wt. % CdCl2) obtained by zone melting was investigated. Techniques for preparing a surface of thermoelectric material and deposition modes of Ni films by magnetron sputtering were developed. The thickness of the Ni contact layer was 300 nm. The determined specific contact resistance was 1.3*10
^-9
Ohm*m
²
.