Redox-Driven Switching Behavior in [Ru(NH₃)₆][Fe(CN)₆]—Unlocking Neuromorphic Potential

Neuromorphic computing aims to replicate the architecture and functionality of the human brain to develop energy-efficient, adaptive computational systems. In this study, we explore electron transfer phenomena in [Ru(NH₃)₆][Fe(CN)₆] films and crystals across various oxidation states, focusing on their potential for neuromorphic applications. The redox-active nature of these complexes enables efficient switching behavior, which is critical for mimicking synaptic activities in neuromorphic systems.
Cyclovoltammetry experiments revealed complex redox behaviors across different oxidation states, emphasizing on the material's capacity for voltage-dependent conductance modulation. This switching behavior suggests that the material can achieve multiple stable conductance states, a key characteristic for neuromorphic functionality. These findings are further supported by experimental data demonstrating distinct transitions between conductance levels in response to varying applied voltages.
To gain a deeper understanding of the underlying mechanisms, Density Functional Theory (DFT) calculations were performed on 2D and 3D [Ru(NH₃)₆][Fe(CN)₆] crystals confined by Au electrodes. Marcus and Marcus-Hush-Chidsey theories were applied to model electron transfer rates, energy barriers, and reaction kinetics. These computational results offer detailed insights into spin multiplicities, stability, and electron transfer pathways, which are crucial for optimizing the material's performance in neuromorphic systems.
These findings provide a strong foundation for the development of redox-active materials in neuromorphic device applications, with the potential to advance the field of brain-inspired computing by enabling efficient, scalable, and adaptive systems.