Electron-Vibron Coupling at Metal-Organic Interfaces from Theory and Experiment

Area of Science:

• Surface Science
• Organic Electronics
• Spectroscopy

Background:

• Metal-organic interfaces are crucial in organic electronics.
• Understanding charge transfer dynamics is key to device performance.
• 1,4,5,8-naphthalene-tetra-carboxylic dianhydride (NTCDA) on Ag(111) serves as a model system.

Purpose of the Study:

• To quantitatively investigate interfacial dynamical charge transfer.
• To determine the characteristics of this charge transfer.
• To elucidate its contribution to infrared activity.

Main Methods:

• Quantitative analysis using infrared absorption spectroscopy.
• Theoretical calculations with dispersion-corrected density functional theory (DFT).
• Analysis of dynamic dipole moments and electron-vibron coupling.

Main Results:

• Interfacial dynamical charge transfer is the primary source of infrared activity.
• This charge transfer correlates with partial charge and density of states.
• Nuclear motion contributes a minor dynamic dipole moment, except for specific modes.

Conclusions:

• Dynamical charge transfer is the dominant mechanism for IR absorption at these interfaces.
• DFT and spectroscopy confirm the significance of charge transfer.
• The findings provide insights into charge transport at metal-organic interfaces.