Tunable Charge‐Density PEDOT:PSS for Application in Post‐Synaptic Organic Neuromorphic Electrodes

Abstract Since the discovery of neuromorphic computing, the search for the ideal hardware technology has been the main focus of technological research and development in the area. Among the candidates, the electrochemical neuromorphic organic device (ENODe) shows promising properties such as low energy consumption, high computing efficiency, and relatively inexpensive units. However, ENODes suffer from long term instability, especially due to electrode degradation. Here, the use of a modified poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) synthesis is proposed to obtain intrinsically low‐charge density PEDOT:PSS inks for application as post‐synaptic electrodes in ENODes. The charge density of the synthesized inks is evaluated by optical spectroscopy, revealing that the amount of oxidizing agent in the synthesis route is directly correlated with the PEDOT:PSS charge density. ENODes fabricated with the synthesized low‐charge density PEDOT:PSS operate in the low‐voltage regime, with good stability and present non‐volatile memory levels. The easy‐to‐implement synthetic approach unlocks new strategies for producing stable and tunable charge‐density materials for constructing the next‐generation of organic neuromorphic devices.