Consecutive Charging of a Molecule-on-Insulator Ensemble Using Single Electron Tunnelling Methods

Area of Science:

• Surface science
• Nanotechnology
• Molecular electronics

Background:

• Understanding charge dynamics in molecular ensembles is crucial for developing novel electronic devices.
• Insulator-supported molecular systems present unique challenges and opportunities for charge manipulation.
• 1,1'-Ferrocenedicarboxylic acid (FDC) is a molecule of interest for its electronic properties.

Purpose of the Study:

• To investigate the local charge state modification of 1,1'-ferrocenedicarboxylic acid molecular ensembles on calcite at room temperature.
• To explore the mechanisms of charge transfer and build-up within these molecular islands.
• To correlate charge modification with structural changes in the adsorbate/surface system.

Main Methods:

• Utilized noncontact atomic force microscopy (NC-AFM) to probe molecular ensembles.
• Employed Kelvin probe force microscopy (KPFM) in conjunction with NC-AFM.
• Performed experiments at room temperature to observe charge dynamics.

Main Results:

• Observed single electron tunneling between the NC-AFM tip and molecular islands.
• Detected successive charge build-up in the sample through consecutive experiments.
• Provided experimental evidence for charge transfer within the molecular islands.

Conclusions:

• Demonstrated the ability to modify and observe local charge states in molecular ensembles.
• Indicated charge transfer and structural relaxation as key processes governing the system's behavior.
• Highlighted the potential for controlled charge manipulation in such systems.