An Au25-R single-molecule tidal diode induced by the asymmetrical coupling

As a basic electronic component, the diode has drawn much attention in single-molecule electronics. However, the single-molecule diode is limited to the conventional diode mode, switching to “on” with a forward voltage and to “off” whenever an opposite voltage is applied. We report on a paradigm for designing a single-molecule tidal diode, which enables gate-controlled reversible rectifying behavior. In the Au25-R single-molecule transistors constructed by us, we observed clear rectification and achieved an electrically controllable reversible diode effect. The backward rectification ratio reached the maximum value of 30 at a negative bias voltage of −30 mV, while the forward rectification ratio was slightly smaller. We used an asymmetrical coupling model and a Landauer resonant tunneling model to explain the reversible diode effect and its dependence on temperature. The integration of bidirectional tunable diodes in a single-molecule device creates an avenue of research and allows the discovery of a set of traffic rules for the electronic world in the future.