Resistive Switching of Self-Assembled Silver Nanowire Networks Governed by Environmental Conditions

Percolating networks formed by coated metallic nanowires have recently shown to exhibit memristive properties, opening a path for the development of neuromorphic systems. In this work, the resistive switching phenomena occurring in percolative networks of silver nanowires (AgNWs) coated with a thin layer of polyvinylpyrrolidone is studied. By performing voltage-driven excursions, the highly-conductive pristine state irreversibly changes to a higher resistance state. Such an electroforming procedure enables the switching among multiple resistance states. The stability and controllability of the resistance levels are found to be highly dependent on the initial state and the environmental conditions. In low relative humidity environments, the system displays the most controlled switching operation, while in high humidity environments the system shows a high conductance level. Samples with hysteretic response display sharp and spontaneous transitions to different resistance states, exhibiting multilevel memory device features. Both behaviors can be associated with regions of high local concentration of AgNWs that can couple or decouple from the conduction paths according to external stimuli. Conductivity is determined at a fundamental level by electrochemical processes at critical junctions in which water molecules play a key role. These results are relevant for the development of AgNWs-based electronics and in-hardware neuromorphic computing.

Automated summary

This paper investigates the resistive switching phenomena in percolative networks of silver nanowires coated with a thin layer of polyvinylpyrrolidone. The system exhibits different conductance levels and resistance state transitions under different environmental conditions, which is significant for the development of AgNWs-based electronics and in-hardware neuromorphic computing.