A bias voltage controlled electrode-molecule interface in single-molecule junctions

Abstract

Tuning the electrode-molecule interface stands at the heart of functional single-molecule devices. Herein, we report that the electrode-molecule interface of difluoro-substituted benzothiadiazole (FBTZ)-based single-molecule junctions can be modulated by the bias voltage. At low bias voltage (100 mV), the dative Au–N linkage is formed and at high bias voltage (600 mV), a covalent Au–C linkage is constructed. These junctions show distinct conductance. Interestingly, dominant charge carriers in Au–N- and Au–C-based junctions are different, as evidenced by dft calculations. These results provide a new strategy for regulating the electrode-molecule interface, which will advance the development of molecular electronics.