Artificial photosynaptic transistors enabled by polypyrrole electrodes for neuromorphic computing.

Organic photosynaptic transistors have unique characteristics, including low-cost, low-temperature processing, and large-area coverage. However, the electrodes of most organic transistors still face great challenges due to the limitation of materials and fabrication processes, which lack the characteristics of environmental stability and high patterning resolution. Here, a solution-processed, mechanically stable and high-precision electrode is proposed, which has excellent interfacial compatibility with the semiconductor layer. Moreover, benefiting from the environmental stability and great performance, our photosynaptic transistor (PST) array can serve as a physical reservoir computing (RC) system, which is used to implement letter and word recognition and gesture classification based on multi-channel surface electromyography (s-EMG) signals. This work provides a strategy to fabricate organic transistors with high resolution and great environmental stability, showing a promising potential of patterned polypyrrole (PPy) electrodes in future organic electronics and commercialized large-scale integration applications.