High Tg cyclic olefin copolymer/Al2O3 bilayer gate dielectrics for flexible organic complementary circuits with low-voltage and air-stable operation

Abstract

Here we present solution-processed ultrathin cyclic olefin copolymer (COC)/Al2O3 bilayer gate dielectrics for low-voltage and flexible N,N′-ditridecyl perylene diimide (PTCDI-C13)-based n-type organic field-effect transistors (OFETs) and their complementary circuits. The PTCDI-C13 thin films grown on the COC/Al2O3 bilayer gate dielectrics formed large and flat grains with thermal treatment, resulting in high OFET performance, and stability in an ambient air atmosphere. Despite the high glass transition temperature of the COC, the COC thin films showed good mechanical flexibility with the application of bending strain, and OFETs with bilayer gate dielectrics showed stable operation up to a strain of 1.0%. Complementary inverters based on the PTCDI-C13 and pentacene OFETs with bilayer dielectrics functioned at a low voltage of 5 V, and exhibited a high gain of 63.