Selective Raman Enhancement with Electronic Sensitivity in Tip-Enhanced Raman Spectroscopy

Area of Science:

• Chemical Physics
• Spectroscopy
• Materials Science

Background:

• Tip-enhanced Raman spectroscopy (TERS) relies on the chemical interaction between the probe tip and molecules.
• Understanding tip-molecule interactions is crucial for interpreting TERS spectra and enhancing resolution.

Purpose of the Study:

• To investigate the influence of TERS tip position on the spectral characteristics of biphenylene (BP) dimers.
• To explore how tip-induced electronic redistributions affect vibrational mode characters and Raman intensity.

Main Methods:

• Density functional theory (DFT) calculations were employed to simulate TERS spectra.
• TERS spectra of biphenylene dimers were computed at 13 distinct tip sites.

Main Results:

• Specific enhancement of vibrational modes involving the antisymmetric stretching of tetra-rings was observed.
• The vibrational strength of specific atoms was found to be tunable by the TERS tip.

Conclusions:

• The study provides an intuitive interpretation of tip-induced electronic effects on vibrational modes in TERS.
• The findings suggest a pathway for improving the spatial resolution of TERS measurements.