Remarkable performance improvement of copper phthalocyanine organic field-effect transistors with polymeric bilayer gate insulator

Abstract CuPc organic field-effect transistors (OFETs) were fabricated based on bilayer gate insulator consisting of polyvinyl alcohol (PVA) and methyl methacrylate co glycidyl methacrylate (P(MMA-GMA)). The complementary property of two polymer materials overcomes the drawbacks of each other, and then improves the dielectric properties of the composite insulator: a higher equivalent permittivity(k ~ 6.0), hydrophobicity, ultra-smooth (1.47 A) and good compatibility with CuPc. The crystal quality of CuPc film have been improved effectively. As a result, a carrier mobility of 6.55 × 10−2 cm2/Vs and a threshold voltage of −3 V have been obtained. The Ids has increased double with the same insulator thickness.