AlScN-based ferroelectric memristor for electrical synapse emulation and light‐stimulated reservoir computing

In this study, we present a multifunctional indium tin oxide (ITO)/aluminum scandium nitride (AlScN)/n⁺ Si ferroelectric memristor for integrated electrical–optical neuromorphic computing. The device, fabricated using radio frequency sputtering, exhibits robust ferroelectricity with an average remanent polarization of 48.46 μC/cm² and stable endurance over 10⁵ cycles. Electrical measurements confirm core synaptic behaviors, including potentiation and depression, with improved linearity and recognition accuracy using incremental pulse schemes. Spike‐dependent plasticity modulated by pulse number, amplitude, and width is also demonstrated. In addition, the device exhibits a volatile photoresponse under 405 nm illumination conditions, enabling optically induced potentiation and depression depending on light intensity, mimicking short‐term synaptic plasticity. Leveraging this dual electrical–optical modulation, we implemented a physical reservoir computing system using optically stimulated devices to process 4‐bit encoded Modified National Institute of Standards and Technology inputs, achieving a classification accuracy of 96.35%. These results highlight the potential of the ITO/AlScN/n⁺ Si memristor as a compact, energy‐efficient platform for next‐generation optoelectronic neuromorphic systems.