A High-Performance Organic Thin-Film Transistor with Parylene/PMMA Bilayer Insulation Based on P3HT

This work introduces a pioneering approach in the development of organic thin-film transistors (OTFTs), featuring a double-layer dielectric structure that combines Poly(para-xylylene)s (Parylene) and poly(methyl methacrylate) (PMMA) to leverage the high dielectric constant and low surface polarity of Parylene with the low dielectric constant and high surface polarity of PMMA. This combination results in devices that showcase significantly enhanced electrical performance, including superior charge carrier mobility, increased current on/off ratios, and greater transconductance. Utilizing poly(3-hexylthiophene) (P3HT) for the active layer, the study demonstrates the advantage of the dual dielectric layers in minimizing hysteresis in the transfer curve, thereby facilitating the systematic growth of the organic active layer and enhancing electrical conductivity over single-layer alternatives. The superior performance of the Parylene/PMMA double-layer insulating structure opens new avenues for the advancement of organic electronics, presenting methodologies for performance optimization and expanding the application spectrum of OTFTs.