Electrochemical gating effect of transition metal complexes for graphene-based single molecular junctions

Activity: SupervisionMaster Dissertation Supervision


Molecular electronics is a field of science that investigates the electronic transport properties of circuits using single molecules as functional building blocks. By connecting one molecule or several molecules oriented in parallel between two electrodes, so-called molecular junctions (MJs) are formed, which are the foundation units of molecular electronics. To integrate molecules into large-scale devices, achieving reliable and reproducible MJs is critical. Now it is possible to directly measure the charge transport through a molecule by a scanning tunneling microscope (STM). The objective of this research is to apply a gate voltage to the single molecular junction (SMJ) containing transition metal redox centers under the asymmetric contacts of gold and graphene, in the hope of achieving the electrochemical gating of such molecular junctions while sweeping different gate voltages. Here the conductance values of Au/Co(Pyterpy)2(PF6)2/graphene and Au/Ru(Pyterpy)2(PF6)2/graphene junctions under different voltages have been measured. A clear off-on-off switching behavior is observed in Au/Co(Pyterpy)2(PF6)2/graphene junctions and due to the restriction of the experimental conditions, only an on-off switching behavior is observed in Au/Ru(Pyterpy)2(PF6)2/graphene junctions. These results reveal that a gate field allows reversibly switching redox modules between oxidized and reduced states.
PeriodJun 2021 → …
Degree of RecognitionInternational