Electrodeposited Reduced Graphene Oxide Enables Long-Term Memory in Neuromorphic Ambipolar Electrolyte-Gated Transistors.

Ambipolar transistors, capable of conducting both electrons and holes, enable the simplification of circuit design by reducing the number of constituting units in circuits and opening new possibilities for low-power electronics, reconfigurable logic circuits, and memory devices. 2D ambipolar semiconductors as graphene and its derivatives, are particularly advantageous in bioelectronics, for their high sensitivity in label-free sensors and their biocompatibility. Here, a novel method for fabricating electrolyte-gated transistors based on reduced graphene oxide (rGO-EGTs) is proposed, which enables precise control over the thickness of deposited rGO. Such rGO-EGTs act as a neuromorphic unit that exhibits tailorable long-term plasticity when driven with pulsed voltage. By applying different numbers of voltage pulses and acting on their amplitudes, it is possible to program multilevel memory with retention timescales over tens of minutes and 6.60 µS writing resolution. This long-term plasticity makes our rGO-EGT promising for nonvolatile memory, computing, and plasticity-based signal pattern recognition.