Thermoplasmonics: quantifying plasmonic heating in single nanowires.

Area of Science:

• Nanotechnology and Materials Science
• Plasmonics and Photonics
• Thermal Physics

Background:

• Plasmonic absorption in metallic nanostructures causes local heating, a phenomenon central to thermoplasmonics.
• Accurate quantification of temperature increases in individual nanostructures remains a significant experimental challenge.
• Thermoplasmonics has broad applications in biomedicine, optoelectronics, and sensing.

Purpose of the Study:

• To quantitatively determine the local temperature increase in single metallic nanostructures.
• To elucidate the underlying plasmonic heating mechanisms through polarization dependence.
• To provide insights for designing nanostructures that effectively utilize optical heating.

Main Methods:

• Utilized metal nanowires exhibiting a transverse plasmon mode.
• Measured optically induced changes in electrical resistance to infer temperature.
• Employed computational modeling to analyze optical heating contributions and thermal transport pathways.

Main Results:

• Successfully quantified temperature increases in single nanostructures.
• Demonstrated a clear dependence of heating on incident light polarization, confirming the plasmonic origin.
• Identified resonant and nonresonant optical heating contributions and primary thermal transport routes.

Conclusions:

• Combined electronic and optical measurements provide a robust method for characterizing nanostructure thermometry.
• The findings establish bounds for optical heating effects in previous experiments.
• Results offer crucial design guidelines for optimizing nanostructures for thermoplasmonic applications.