Flexible Organic Thin Film Transistors Incorporating a Biodegradable CO2-Based Polymer as the Substrate and Dielectric Material

Abstract

Employing CO2-based polymer in electronic applications should boost the consumption of CO2 feedstocks and provide the potential for non-permanent CO2 storage. In this study, polypropylene carbonate (PPC) is utilized as a dielectric and substrate material for organic thin film transistors (OTFTs) and organic inverter. The PPC dielectric film exhibits a surface energy of 47 mN m-1, a dielectric constant of 3, a leakage current density of less than 10-6 A cm-2, and excellent compatibility with pentacene and PTCDI-C8 organic semiconductors. Bottom-gate top-contact OTFTs are fabricated using PPC as a dielectric; they exhibits good electrical performance at an operating voltage of 60 V, with electron and hole mobilities of 0.14 and 0.026 cm2 V-1 s-1, and on-to-off ratios of 105 and 103, respectively. The fabricated p- and n-type transistors were connected to form a complementary inverter that operated at supply voltages of 20 V with high and low noise margins of 85 and 69%, respectively. The suitability of PPC as a substrate is demonstrated through the preparation of PPC sheets by casting method. The fabricated PPC sheets has a transparency of 92% and acceptable mechanical properties, yet they biodegraded rapidly through enzymatic degradation when using the lipase from Rhizhopus oryzae.