Surface-Enhanced Raman Spectroscopy (SERS) Study Using Oblique Angle Deposition of Ag Using Different Substrates

Area of Science:

• Materials Science
• Nanotechnology
• Spectroscopy

Background:

• Surface-enhanced Raman spectroscopy (SERS) is a powerful technique for sensitive molecular detection.
• The efficiency of SERS is highly dependent on the morphology and arrangement of plasmonic nanostructures.
• Optimizing the fabrication of silver (Ag) nanostructures is crucial for enhancing SERS performance.

Purpose of the Study:

• To investigate the effect of deposition rate and substrate material on the SERS efficiency of oblique angle deposited silver (Ag).
• To optimize the deposition rate for achieving maximum SERS efficiency.
• To analyze the morphology of Ag nanostructures formed on different substrates and correlate it with SERS performance.

Main Methods:

• Oblique angle deposition of silver (Ag) was performed at varying deposition rates.
• Ag nanostructures were deposited on diverse substrates including SiO2, sapphire, tungsten, graphene, and plasma-treated SiO2.
• Morphological analysis of the deposited Ag nanostructures was conducted.
• SERS efficiency was measured and compared across different deposition conditions and substrates.

Main Results:

• The optimal deposition rate for maximum SERS efficiency was determined to be 2.4 Å/s.
• Ag nanostructures deposited on SiO2, sapphire, and tungsten exhibited straight nanorod morphology and high SERS efficiency.
• Ag deposited on graphene and plasma-treated SiO2 showed aggregation, leading to reduced SERS efficiency due to high surface energy.

Conclusions:

• The deposition rate and substrate material are critical parameters for fabricating high-performance SERS substrates.
• A deposition rate of 2.4 Å/s is optimal for Ag nanorod formation with high SERS efficiency.
• Substrates like SiO2, sapphire, and tungsten are suitable for achieving efficient SERS enhancement with Ag nanostructures, while graphene and treated SiO2 require further optimization.