Stability improvement in flexible low-voltage organic field-effect transistors with complementary polymeric dielectrics

The stability in terms of electrical, mechanical and thermal performance, is highly desirable for practical application of flexible electronics. Here, we report the stability improvement for pentacene-based flexible organic filed-effect transistors (OFETs) with complementary polymeric dielectrics, in which the net structured cross-linked poly(4-vinylphenol) (cPVP) layer was sandwiched between two ultrathin poly-(methyl methacrylate) (PMMA) layers. The core-shell-like structured dielectrics showed improved electrical insulating property by tuning the surface morphology and termination of the pinholes, enabling a 4 V-driven flexible OFET device with a high mobility of 0.72 cm²/V and excellent bias-stress stability in air. Under the tensile bending strain, the relationship between the parallel/vertical bending directions, dynamic or static bending modes and device performances were quantitatively investigated. Moreover, this flexible OFETs has a thermal operation margin up to at least 90 °C. The interfacial compatibility between the top PMMA layer and Pentacene was responsible for the enhanced stability performances. Our approach provides future possibilities of using hybrid polymeric dielectrics for highly stable flexible OFETs.