Remote‐Controllable Interfacial Electron Tunneling at Heterogeneous Molecular Junctions via Tip‐Induced Optoelectrical Engineering

Abstract

Abstract Molecular electronics enables functional electronic behavior via single molecules or molecular self‐assembled monolayers, providing versatile opportunities for hybrid molecular‐scale electronic devices. Although various molecular junction structures are constructed to investigate charge transfer dynamics, significant challenges remain in terms of interfacial charging effects and far‐field background signals, which dominantly block the optoelectrical observation of interfacial charge transfer dynamics. Here, tip‐induced optoelectrical engineering is presented that synergistically correlates photo‐induced force microscopy and Kelvin probe force microscopy to remotely control and probe the interfacial charge transfer dynamics with sub‐10 nm spatial resolution. Based on this approach, the optoelectrical origin of metal–molecule interfaces is clearly revealed by the nanoscale heterogeneity of the tip‐sample interaction and optoelectrical reactivity, which theoretically aligned with density functional theory calculations. For a practical device‐scale demonstration of tip‐induced optoelectrical engineering, interfacial tunneling is remotely controlled at a 4‐inch wafer‐scale metal–insulator–metal capacitor, facilitating a 5.211‐fold current amplification with the tip‐induced electrical field. In conclusion, tip‐induced optoelectrical engineering provides a novel strategy to comprehensively understand interfacial charge transfer dynamics and a non‐destructive tunneling control platform that enables real‐time and real‐space investigation of ultrathin hybrid molecular systems.

Keywords

• photo‐induced force microscopy
• Kelvin probe force microscopy
• molecular tunneling junction
• interfacial charge transfer
• DFT calculation