Improving the Long-Term Stability of PbTe-Based Thermoelectric Modules: From Nanostructures to Packaged Module...

Area of Science:

• Materials Science
• Solid State Physics
• Energy Conversion

Background:

• Nanostructured lead telluride (PbTe) is a leading thermoelectric material for intermediate temperatures.
• Fabrication challenges include material stability, particularly nanoprecipitates, and electrical contact bonding.
• Improving module durability and preventing material-electrode interactions are crucial for practical applications.

Purpose of the Study:

• To investigate the thermal stability of nanoprecipitates in p-type PbTe.
• To develop and optimize a novel module architecture for enhanced durability and performance.
• To evaluate the long-term operational stability and power generation characteristics of the developed module.

Main Methods:

• In situ high-temperature transmission electron microscopy (TEM) for nanoprecipitate stability analysis.
• Finite element method (FEM) simulations for thermal stress and power generation optimization.
• Module fabrication using nanostructured p-type and n-type PbTe with flexible diffusion barriers and interconnecting electrodes.

Main Results:

• Nanoprecipitates in p-type Pb_0.973Na_0.02Ge_0.007Te remained stable up to ~786 K.
• The new module architecture effectively prevented material-electrode interactions and reduced thermal stress.
• A maximum conversion efficiency of ~6.8% was achieved for a temperature difference of ~480 K.
• Long-term operation (~740 h) showed only a ~3% reduction in output power and efficiency.

Conclusions:

• The developed module architecture ensures good long-term stability for nanostructured PbTe thermoelectric generators.
• The findings address key challenges in fabricating durable and efficient PbTe-based power modules.
• This work paves the way for practical applications of high-performance thermoelectric devices.