Broadband and Spectrally Selective Photothermal Conversion through Nanocluster Assembly of Disordered Plasmonic...

Area of Science:

• Nanophotonics and Plasmonics
• Materials Science
• Energy Conversion

Background:

• Plasmonic metasurfaces enable efficient light absorption and photothermal conversion via nonradiative decay.
• Existing metasurfaces face challenges with limited spectral ranges, expensive fabrication, and scalability.

Purpose of the Study:

• To demonstrate a new disordered plasmonic metasurface for tunable photothermal conversion.
• To overcome fabrication and spectral limitations of current plasmonic metasurfaces.
• To introduce a method for temperature measurement using surface-enhanced Raman spectroscopy (SERS).

Main Methods:

• Fabrication of disordered metasurfaces by densely packing ultrasmall plasmonic nanoclusters on an optical cavity.
• Utilizing single-walled carbon nanotubes (SWCNTs) as SERS probes for in-situ temperature measurement.
• Characterization of broadband and reconfigurable absorption properties across the visible spectrum.

Main Results:

• Demonstrated a disordered metasurface with broadband or reconfigurable visible light absorption.
• Achieved continuous wavelength-tunable photothermal conversion.
• Successfully employed SWCNTs for accurate temperature measurement of the metasurface.

Conclusions:

• The bottom-up fabricated disordered plasmonic system offers efficient photothermal conversion and overcomes limitations of top-down approaches.
• The developed metasurface is a versatile platform for tunable energy harvesting and hot-electron applications.
• This work presents a scalable and cost-effective approach to advanced plasmonic devices.