Bonding of Bi2Te3-Based Thermoelectric Legs to Metallic Contacts Using Bi0.82Sb0.18 Alloy
Thermoelectrics is gaining increased attention as a renewable direct energy conversion method from heat to electricity. The most efficient and up-to-date thermoelectric materials for temperatures of up to 250°C are (Bi1−xSbx)2 (Te1−ySey)3 alloys. In the current research, to discover practical thermoelectric power generation devices capable of operation at such temperatures, Bi0.82Sb0.18 alloy was considered as a lead-free high-temperature (<250°C) solder composition for bonding of n-type Bi2Te2.4Se0.6 and p-type Bi0.4Sb1.6Te3 legs into Cu, Ag, Ni and Fe metallic bridges. In the case of Cu, fine contacts with low electrical contact resistance of ∼1.5 ± 0.5 mΩ mm2 were observed upon soldering at 350°C.