Analog Synaptic Plasticity in 2D Layered Material Iontronic Memtransistors for Brain‐Inspired Computing

ABSTRACT

A simple iontronic memtransistor capable of emulating synaptic plasticity and cognitive functions showcases high performance and low energy consumption, fostering admiration for its efficiency. Here, we report the versatile, high‐performance memtransistor behavior of a solid polymer electrolyte‐gated few‐layer thick two‐dimensional molybdenum disulfide (2D MoS ₂ ) channel. Transfer characteristics exhibit pinched hysteresis, confirming n‐channel enhancement‐mode operation, supported by the low‐voltage drain characteristics under the influence of the electrical double layer (EDL) formed by iontronic gating. The memtransistor shows a reproducible non‐volatile memory window in its transfer characteristics with conductance retention exceeding 10 ³ s and endurance beyond 10 ³ switching cycles. Mechanistic studies reveal coupled slow ion migration and dipolar relaxation processes coexisting with purely electronic transport in the 2D material channel, highlighting mixed ionic‐electronic carrier dynamics. Using tailored input‐output pulse schemes, the device demonstrates key synaptic and cognitive learning functionalities with lower energy consumption per event and faster response speed down to the microsecond regime. Furthermore, higher‐order behaviors such as Atkinson‐Shiffrin‐type memory behavior, Pavlovian associative learning, and logic gate operations are achieved. These achievements confirm the potential of our 2D iontronic memtransistor (IMT) as a reliable, reproducible building block for next‐generation brain‐inspired computing systems.