Synthesis of Large‐Area 2D Prussian Blue as Ion‐Transport Channels for Non‐Volatile Memristors

Why It Matters

The breakthrough provides a reproducible pathway to embed ion‑conducting 2D coordination polymers in electronic hardware, unlocking high‑performance, low‑power memory and neuromorphic computing architectures.

Key Takeaways

• Interfacial synthesis yields continuous 2D Prussian blue films.
• Film thickness tunable from 2 nm to several hundred nanometres.
• Memristors show 10⁶ on/off ratio across 1.5 µm gaps.
• Device stability exceeds 150 cycles with >6 h retention.
• Approach scalable to other coordination polymer thin films.

Pulse Analysis

The integration of Prussian blue into modern electronics has long been hampered by its three‑dimensional crystal habit, which resists exfoliation and leads to grain‑boundary‑rich nanoparticle films. By exploiting a liquid‑liquid interfacial reaction, the authors confine nucleation to a planar zone, allowing layer‑by‑layer growth of FeFe sheets that are both large in lateral dimension and uniform in thickness. This method sidesteps the rapid bulk precipitation that plagued earlier solvothermal routes, delivering films that can be directly transferred onto silicon substrates without the need for post‑deposition annealing.

When these 2D films serve as the active layer in electrochemical metallisation (ECM) memristors, they act as highly directional ion‑transport channels. The continuous framework supports swift Ag⁺ migration, enabling filament formation over micrometre‑scale gaps and producing on/off resistance ratios near one million. Such performance metrics—combined with over six hours of data retention and stable cycling—position these devices as strong candidates for low‑energy, non‑volatile memory and for emulating synaptic behavior in neuromorphic circuits, where long‑range ionic conduction is essential.

Beyond memory, the scalable synthesis opens avenues across catalysis, energy storage, and sensor technologies that demand thin, ion‑conductive, and surface‑active layers. The ability to tune film thickness and extend the interfacial approach to other metal‑cyanide frameworks could accelerate the development of bespoke coordination‑polymer membranes for selective ion sieving or redox‑active electrodes. As the field moves toward heterogeneous integration of functional 2D materials, this work demonstrates that coordination polymers can achieve the same level of processability and device reliability traditionally reserved for graphene‑family materials.