Vibrational Frequency Used as Internal Clock Reference to Access Molecule-Metal Charge-Transfer Times

Area of Science:

• Surface science and condensed matter physics.
• Investigating ultrafast interfacial charge dynamics.

Background:

• Charge transfer at molecule-metal interfaces is vital for optoelectronic devices, occurring on femtosecond timescales.
• Understanding charge transfer at the Fermi energy in electronic ground states remains challenging.

Purpose of the Study:

• To demonstrate a method for accessing and characterizing dynamical charge transfer at the Fermi energy.
• To utilize vibrational excitations to probe ultrafast interfacial electron dynamics.

Main Methods:

• Employing vibrational excitations to induce and observe charge transfer.
• Analyzing nonadiabatic electron-vibron coupling effects.
• Interpreting distinct asymmetric line shapes in spectroscopic data.

Main Results:

• Observed distinct asymmetric line shapes resulting from nonadiabatic electron-vibron coupling.
• Established a method to probe charge transfer dynamics at the Fermi level.
• Utilized vibrational oscillations as an internal clock to determine charge transfer timescales.

Conclusions:

• Vibrational excitations provide a novel route to study interfacial charge transfer dynamics at the Fermi energy.
• Electron-vibron coupling signatures offer insights into the characteristic timescales of these processes.
• This approach enhances understanding of fundamental processes relevant to optoelectronic device functionality.