Remote-Controllable Interfacial Electron Tunneling at Heterogeneous Molecular Junctions via Tip-Induced...

Area of Science:

• Molecular electronics
• Nanoscale science
• Surface science

Background:

• Molecular electronics offers unique opportunities for miniaturized devices using single molecules or self-assembled monolayers.
• Observing charge transfer dynamics in molecular junctions is hindered by interfacial charging and background signals.
• Current methods lack the resolution and control needed for detailed optoelectrical analysis.

Purpose of the Study:

• To develop a novel technique for remote control and probing of interfacial charge transfer dynamics in molecular systems.
• To overcome limitations in observing optoelectrical phenomena at the molecular scale.
• To demonstrate a practical application in device-scale engineering.

Main Methods:

• Synergistic correlation of photo-induced force microscopy (PIFM) and Kelvin probe force microscopy (KPFM).
• Tip-induced optoelectrical engineering for remote control and probing.
• Sub-10 nm spatial resolution analysis.
• Density functional theory (DFT) calculations for theoretical validation.

Main Results:

• Clear elucidation of the optoelectrical origin of metal-molecule interfaces at the nanoscale.
• Observation of nanoscale heterogeneity in tip-sample interactions and optoelectrical reactivity.
• Demonstration of remote control of interfacial tunneling in a wafer-scale metal-insulator-metal capacitor.
• Achieved a 5.211-fold current amplification using a tip-induced electrical field.

Conclusions:

• Tip-induced optoelectrical engineering provides a new strategy for understanding interfacial charge transfer dynamics.
• Enables non-destructive, real-time, and real-space investigation of ultrathin hybrid molecular systems.
• Offers a versatile platform for controlling tunneling in molecular electronic devices.