Superionic Silver Halide Solid Electrolyte: Dielectric Property and Iontronic Memtransistor Application for Bioinspired Computing

Technology like high‐level parallel information processing and storage in the brain remains a dream to the researchers using conventional solid‐state electronics. Here, a robust thin film bilayer superionic dielectric of poly(ethylene oxide) (PEO) and rubidium silver iodide (RbAg4I5) is developed to fabricate solid‐state iontronic synaptic memtransistors, which can serve as the basic building blocks for the hardware‐implementation of neuromorphic computing. X‐ray photoelectron spectroscopy and impedance measurements precisely confirm the stoichiometric composition of RbAg4I5 and dielectric nature combining with a PEO layer, respectively. The superionic bilayer PEO/RbAg4I5 gating effectively modulates the channel conductance analogously and displays memtransistor functionality. Interestingly, the transfer curves depict a colossal hysteresis yielding negative differential transconductance of peak‐to‐valley ratio up to 5 × 103 after the gate‐controlled resistive switching. Systematic electrical characterizations reveal a variety of synaptic behaviors, including the inhibitory postsynaptic current, paired‐pulse depression, and potentiation/depression curve. Finally, an artificial neural network for off‐chip digit recognition is simulated to assess the performance of the device for the neuromorphic application and achieved a test accuracy of 95.94% on the Modified National Institute of Standards and Technology dataset. A robust solid‐state iontronic synaptic memtransistor is developed using a bilayer thin‐film dielectric of poly(ethylene oxide) and superionic rubidium silver iodide (RbAg4I5), which can serve as the basic building blocks for neuromorphic computing hardware‐implementation. The transfer curves of this device depict a colossal hysteresis of resistive switching and yield an interesting signature of negative differential transconductance.