Disordered Ballistic Bismuth Nano-waveguides for Highly Efficient Thermoelectric Energy Conversion

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Electronic ballistic waveguides, like nanowires, show potential for highly efficient thermoelectric (TE) devices.
• Achieving optimal TE efficiency requires precise control over structural variations or tunable disordered structures, but established methods are lacking.

Purpose of the Study:

• To develop and optimize disordered bismuth waveguides for enhanced thermoelectric performance.
• To investigate the formation and structural tuning of these waveguides using electromigration.

Main Methods:

• Fabrication of disordered bismuth waveguides using electromigration.
• Structural tuning of waveguides via electromigration to maximize thermoelectric efficiency.
• Measurement of waveguide conductance and stability.

Main Results:

• Disordered bismuth waveguides were successfully formed and tuned by electromigration.
• The most efficient TE waveguides exhibited conductance in the sub quantum of conductance regime.
• These electromigrated structures demonstrated significantly higher stability compared to single molecule junctions.

Conclusions:

• Electromigration provides a viable method for fabricating and optimizing disordered waveguides for high-performance thermoelectric devices.
• The sub quantum conductance regime is crucial for achieving maximum TE efficiency in these nanostructures.
• The enhanced stability of these bismuth waveguides offers a promising advancement for practical thermoelectric applications.