One-Pot and Mask-Less Realization Approach for Polypyrrole–Polydopamine-Based Organic Electrochemical Transistors

Organic electrochemical transistors (OECTs) are organic-based devices that are gaining growing interest from the scientific community thanks to the possibility of exploiting their electron/ion transduction properties in multiple applications. Typically designed starting from commercial PEDOT:PSS dispersions and multistep photolithographic methods, few examples of OECTs realized with different methodologies and protocols and diverse conductive polymers have been reported so far. Here, we report a facile, reliable, and mask-less electrochemical approach for realizing hybrid polypyrrole–polydopamine (PPy_PDA)-based OECTs. The proposed strategy ensures the control of the conductive channel’s properties while maintaining low-cost and low-waste channel fabrication. The presented method allows the manufacturing of a well-performing OECT with a low voltage range (<1 V), remarkable transconductance (gm = 0.26 mS), and excellent stability to pulse stimulation. The OECT functioning properties are paired and put in perspective with classical electrical (i.e., 2-point probe method) characterizations, along with cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) techniques, and structural analysis (i.e., Raman spectroscopy). The collected results convincingly demonstrate that the proposed approach would represent a simple yet effective route for exploiting PPy in OECT applications.