Generic dynamic molecular devices by quantitative non-steady-state proton/water-coupled electron transport kinetics

Dynamic molecular devices operating with time-and history-dependent performance raised new challenges for the fundamental study of microscopic non-steady state charge transport as well as functionalities that are not achievable by steady state devices. In this study, we reported a generic dynamic mode of molecular devices by addressing the transient redox state of ubiquitous quinone molecules in the junction by proton/water transfer. The diffusion limited slow proton/water transfer-modulated fast electron transport, leading to a non-steady state transport process, as manifested by the negative differential resistance, dynamic hysteresis, and memory like behavior. A quantitative paradigm for the study of the non-steady state charge transport kinetics was further developed by combining the theoretical model and transient state characterization, and the principle of the dynamic device can be revealed by the numerical simulator. On applying pulse stimulation, the dynamic device emulated the neuron synaptic response with frequency-dependent depression and facilitation, implying a great potential for future nonlinear and brain-inspired devices.

Automated summary

This study presents a generic dynamic mode of molecular devices by utilizing the transient redox state of quinone molecules through proton/water transfer. The resulting diffusion-limited proton/water transfer modulates electron transport, leading to non-steady state charge transport with features such as negative differential resistance, dynamic hysteresis, and memory-like behavior. A quantitative paradigm for studying non-steady state charge transport kinetics is developed, and the principle of the dynamic device is revealed through numerical simulation. Application of pulse stimulation shows that the dynamic device can emulate the synaptic response of neurons, suggesting potential for future nonlinear and brain-inspired devices.