Structure-Dependent Chiroptical Properties of Twisted Multilayered Silver Nanowire Assemblies

Area of Science:

• Plasmonics and Nanophotonics
• Chiral Metamaterials
• Optical Engineering

Background:

• Chiroptical properties of plasmonic metasurfaces are architecture-dependent.
• Limited methods exist for tunable chiroptical properties across UV-Vis-NIR ranges.
• Nanowire assembly offers potential for tailored optical responses.

Purpose of the Study:

• To demonstrate tunable chiroptical properties of helical nanostructures.
• To explore the impact of architecture on circular dichroism (CD) intensity and spectral shape.
• To establish design principles for broad wavelength tunability.

Main Methods:

• Helical nanostructures fabricated using grazing incidence spraying and Layer-by-Layer assembly.
• Silver nanowires utilized as building blocks.
• Transfer matrix method employed for optical property modeling.

Main Results:

• Achieved finely tunable chiroptical properties over a broad wavelength range.
• Demonstrated control over CD intensity (ellipticity > 13°, g-factor up to 1.6) via layer orientation.
• Showcased nanometer-scale tuning of layer spacing to modify CD spectra shape.
• Validated experimental findings with a transfer matrix model.

Conclusions:

• Simple design principles enable precise tuning of chiroptical properties in silver nanowire helical nanostructures.
• The developed method offers a versatile platform for creating advanced chiral metamaterials.
• This work advances the design and fabrication of nanostructured materials with tailored optical functionalities.