Using Surface-Enhanced Raman Spectroscopy to Probe Surface-Localized Nonthermal Plasma Activation.

Area of Science:

• Surface Science
• Plasma Physics
• Materials Science

Background:

• Low-temperature, nonthermal plasmas create complex surface environments.
• Plasma-generated species cause localized thermalization upon surface impact.
• Understanding surface heating is critical for plasma-driven processes.

Purpose of the Study:

• To develop and present a Raman thermometry method for quantifying surface heating.
• To investigate surface temperature increases induced by low-temperature plasmas.
• To correlate plasma parameters with observed surface temperature changes.

Main Methods:

• Utilized a nanostructured silver substrate for enhanced Raman signal detection.
• Employed phenyl phosphonic acid as a molecular probe for vibrational excitation measurement.
• Applied Raman thermometry to quantify surface temperature increases.

Main Results:

• Measured significant vibrational excitation of the phenyl group, indicating substantial surface heating.
• Quantified an approximate 80 °C surface temperature increase at a plasma density of 2 × 10^10 cm^-3.
• Demonstrated the effectiveness of Raman thermometry in complex plasma environments.

Conclusions:

• Surface-localized thermal effects in low-temperature plasmas can be accurately quantified.
• Raman thermometry provides a valuable tool for characterizing plasma-induced surface heating.
• Further characterization of these thermal effects is essential for optimizing plasma-surface reaction processes.