Current progress and future challenges in thermoelectric power generation: From materials to devices

Thermoelectric (TE) devices for power generation have been attracting increasing attention on account of their advantages such as solid-state operation, good stability, and high reliability. This paper presents an overview of the design principle, fabrication methods and testing technology of TE power generation devices. Particular attention is paid to skutterudite-based devices regarding electrode fabrication, barrier layer design, interface optimization, protective coating, and evaluation of elements and modules. The development of Bi2Te3-based devices for power generation focusing specifically on the optimization of Bi2Te3/electrode joints and fabrication and evaluation of Bi2Te3-based modules is summarized. The future challenges concerning TE devices for power generation are discussed.

Thermoelectric Devices for Power Generation: Recent Progress and Future Challenges

https://onlinelibrary.wiley.com/doi/epdf/10.1002/admt.201700256

Thermoelectric Devices: A Review of Devices, Architectures, and Contact Optimization

Key issues in development of thermoelectric power generators: High figure-of-merit materials and their highly conducting interfaces with metallic interconnects

Traditional processes of making contacts (metallization layer) onto bulk crystalline Bi2Te3-based materials do not work for nanostructured thermoelectric materials either because of weak bonding strength or an unstable contact interface at temperatures higher than 200 °C. Hot pressing of nickel contact onto nanostructured thermoelectric legs in a one-step process leads to strong bonding. However, such a process results in large contact resistance in n-type Ni/Bi2Te2.7Se0.3/Ni legs, although not in p-type Ni/Bi0.4Sb1.6Te3/Ni legs. A systematic study was carried out to investigate the detailed reaction and diffusion at the interface of the nickel layer and n-type Bi2Te3-based thermoelectric material layer. We found that a p-type region formed within the n-type Bi2Te2.7Se0.3 during hot pressing due to Te deficiency and Ni doping, leading to a large contact resistance.

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Understanding of the contact of nanostructured thermoelectric n-type Bi2Te2.7Se0.3 legs for power generation applications

A cost-effective and reliable Ni-Au contact on nanostructured Bi2Te3-based alloys for a solar thermoelectric generator (STEG) is reported. The use of MPS SAMs creates a strong covalent binding and more nucleation sites with even distribution for electroplating contact electrodes on nanostructured thermoelectric materials. A reliable high-performance flat-panel STEG can be obtained by using this new method.

Ya Huei Chang

Papers

Reliable contact fabrication on nanostructured Bi2Te3-based thermoelectric materials