Mo/Ni and Ni/Ta–W–N/Ni thin-film contact layers for (Bi,Sb)2Te3-based intermediate-temperature thermoelectric elements

Abstract

We have examined the possibility of utilizing thin-film contact layers for producing reliable Ohmic contacts to proposed intermediate-temperature (Bi,Sb)2Te3-based thermoelectric materials with improved thermoelectric properties, which allow the working temperature range to be extended to 600 K. Three contact configurations have been produced by ion-plasma magnetron sputtering: a single Ni layer, Mo/Ni bilayer, and Ni/Ta–W–N/Ni three-layer system. It has been shown that reliable contacts can be produced using Mo/Ni and Ni/Ta–W–N/Ni layers, which prevent interdiffusion between the materials to be joined and ensure good adhesion to the thermoelectric element.