Full thermoelectric characterization of a single molecule

Area of Science:

• Materials Science
• Nanotechnology
• Condensed Matter Physics

Background:

• Molecules offer tunable properties for high thermoelectric efficiency in energy conversion.
• Demonstrating molecular thermoelectric capabilities at room temperature (300 K) remains a challenge.
• A comprehensive technique to measure thermal and electrical properties, including phonon conduction, is lacking.

Purpose of the Study:

• To develop and apply a novel technique for measuring single-molecule thermoelectric properties at room temperature.
• To experimentally determine the figure of merit (zT) of a specific molecule at 300 K.
• To validate the measurement protocol with a known molecular system.

Main Methods:

• Combined the break junction technique with a suspended heat-flux sensor.
• Measured total thermal and electrical conductance of a single molecule.
• Determined the Seebeck coefficient and extracted the figure of merit (zT).

Main Results:

• Successfully measured the experimental zT of a single DHBT-OPE3-An molecule at room temperature.
• Results align with theoretical predictions from density functional theory and molecular dynamics.
• Validated the protocol using SAc-OPE3, confirming its reliability.

Conclusions:

• This work presents the first simultaneous measurement of single-molecule thermoelectric properties and zT at room temperature.
• The developed technique opens avenues for screening diverse molecules for thermoelectric applications.
• Enables advancements in molecular-scale energy conversion technologies.