High-temperature Bi2Te3 thermoelectric generator fabricated using Cu nanoparticle paste bonding

• Published in: Journal of alloys and compounds Vol. 896; p. 163060
• Main Authors: Chung, Seok-Hwan, Kim, Jong Tae, Kim, Hoyoung, Kim, Jeongmin, Kim, Dong Hwan
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 10-03-2022; Elsevier BV
• Subjects: Bi2Te3; Bismuth tellurides; Bonding; Commercialization; Copper; Copper nanoparticle; Devices; Electrodes; High temperature; Joining; Lead-free solder; Nanoparticles; Operating temperature; Plasma sintering; Spark plasma sintering; Thermal stability; Thermoelectric generators; Thermoelectric power generator; Thermoelectricity; Bi2Te3; Thermoelectric power generator; Spark plasma sintering; Lead-free solder; Copper nanoparticle
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.163060

•The application of copper nanoparticle paste is investigated.•The CNP is used as bonding material for Cu electrodes and thermoelectric materials.•The CNP bonding is an effective method for high-temperature TEG devices.
For the successful commercialization of Bi2Te3-based thermoelectric generator (TEG) devices, not only highly efficient TE materials, but also reliable bonding materials with high thermal stability are essential. In this study, we investigated the application of Cu nanoparticle paste (CNP) bonding for increasing the operating temperature of Bi2Te3-based TEG devices. Six-chip TEG devices were fabricated by joining surface-metalized Bi2Te3-based TE chips and Cu electrodes by CNP bonding. The optimal bonding was achieved when spark plasma sintering was carried out at 310–320 °C and 15 MPa. The 6-chip Bi2Te3-based TEG devices showed a maximum output power of 50–60 mW at the hot-side temperature of 400 °C (∆T= 380 °C) and maintained almost the same output power after five thermal cycles. The scanning electron microscopy images of the thermally cycled electrodes further confirmed the robustness of the Cu nanoparticle joints. This work provides an effective method for joining TE chips and Cu electrodes for high-temperature TEG devices.