High-sensitivity stark spectroscopy obtained by surface plasmon resonance measurement

Area of Science:

• Physical Chemistry
• Surface Science
• Spectroscopy

Background:

• The Stark effect describes how electric fields alter molecular electronic states.
• Conventional Stark spectroscopy methods can be complex and require specialized equipment.
• Understanding molecular behavior under electric fields is crucial in various chemical and physical applications.

Purpose of the Study:

• To develop a high-sensitivity Stark spectroscopy method utilizing surface plasmon resonance (SPR).
• To extract Stark spectra of molecular adsorbates using SPR angular shifts and Kramers-Kronig relations.
• To demonstrate the capability of this method for analyzing electronic states and determining adsorbate coverage.

Main Methods:

• Measuring SPR as a function of incident light wavelength.
• Applying an external electric field to molecular adsorbates on a surface.
• Utilizing the Kramers-Kronig relation to derive Stark spectra from SPR angular shifts.
• Analyzing the SPR angular shift for adsorbate coverage determination.

Main Results:

• Successfully extracted Stark spectra comparable to conventional methods for organic adsorbates.
• Demonstrated high sensitivity in Stark spectroscopy due to precise SPR angular shift measurements.
• Showcased the ability to determine adsorbate coverage from SPR angular shifts.

Conclusions:

• SPR-based Stark spectroscopy offers a sensitive and precise alternative to conventional methods.
• This technique provides valuable insights into the electronic properties of molecular adsorbates under electric fields.
• The method is versatile, allowing for both spectral analysis and coverage determination.