Epitaxial Aluminum Surface-Enhanced Raman Spectroscopy Substrates for Large-Scale 2D Material Characterization

Area of Science:

• Plasmonics
• Nanotechnology
• Spectroscopy

Background:

• Surface-enhanced Raman spectroscopy (SERS) is crucial for detecting trace analytes via vibrational fingerprints.
• Current SERS methods lack uniform, reproducible, and stable substrates for controlled plasmonic hotspots across a broad spectral range.

Purpose of the Study:

• To introduce epitaxial aluminum films as a scalable plasmonic platform for SERS.
• To evaluate the uniformity and performance of these aluminum substrates for SERS applications.

Main Methods:

• Utilizing atomically thin transition metal dichalcogenide monolayers as benchmark analytes to assess substrate uniformity.
• Comparing the SERS performance of epitaxial aluminum substrates with silver counterparts using UV (325 nm) and visible (532 nm) excitation wavelengths.

Main Results:

• Epitaxial aluminum films exhibit excellent uniformity, validated by transition metal dichalcogenide monolayer analysis.
• Aluminum substrates show distinctive spectral capabilities in the UV range.
• Aluminum substrates perform comparably to silver substrates in the visible range, defying predictions based solely on dielectric functions.

Conclusions:

• Epitaxial aluminum films represent a promising, scalable plasmonic platform for SERS.
• The superior surface and interface properties of epitaxial aluminum contribute to its high performance in SERS.
• These findings open new avenues for developing advanced SERS substrates.