Dual-Vibration-Assisted Charge Transport Through Hexabenzocoronene in Single-Molecule Junctions

Gaining deep understanding and effective regulation of the charge transport mechanism within molecular junctions is essential for the development of electronic devices. In this work, a series of hexabenzocoronene-based single-molecule junctions are successfully constructed, and their temperature-dependent charge transport properties are studied. It is found that rotational vibrations of both benzene and hexabenzocoronene rings are sequentially excited as the temperature increases, and the electron-vibration coupling enhances charge tunneling. In addition, the transition temperature between distinct vibration-assisted tunneling modes and the activation energies show strong correlations with the molecular vibration frequency and molecular length. This study unveils the distinct dual-vibration-assisted molecular tunneling mechanism, significantly enhancing the ability to precisely control molecular charge transport and develop functional molecular devices.