Screening Metal Electrodes for Thermoelectric PbTe.

Area of Science:

• Materials Science
• Solid State Physics
• Thermoelectrics

Background:

• Lead telluride (PbTe) exhibits excellent thermoelectric properties for power generation between 300-600 °C.
• Effective device performance relies heavily on stable electrical and thermal contacts between PbTe and metal electrodes.
• Chemical inertness and minimal diffusion are critical factors for selecting suitable electrode materials.

Purpose of the Study:

• To investigate and rank the diffusion behavior of 12 potential metal electrodes in PbTe.
• To identify electrode materials with low diffusion coefficients and interfacial contact resistivity for PbTe.
• To determine the most suitable electrode material for enhancing PbTe-based thermoelectric devices.

Main Methods:

• Fabrication and analysis of PbTe diffusion couples with 12 different metal electrodes.
• Measurement of diffusion coefficients for each metal-PbTe interface.
• Evaluation of interfacial contact resistivity and chemical compatibility at relevant temperatures.

Main Results:

• Cobalt (Co) demonstrated the lowest diffusion coefficient among all tested electrodes.
• Co exhibited low interfacial contact resistivity and remained chemically inert with PbTe.
• Co showed excellent temperature compatibility for sintering processes.

Conclusions:

• Cobalt (Co) is identified as a superior electrode material for PbTe thermoelectric applications.
• The findings highlight the importance of low diffusion and contact resistivity in electrode selection.
• The methodology can be applied to select electrodes for other thermoelectric materials.