Ambipolar organic field-effect transistor using gate insulator hysteresis

An organic field-effect transistor based on a copper-phthalocyanine and cyanoethylpullulan gate insulator showed ambipolar operation using gate insulator hysteresis, which appeared at less than 1mHz. The gate insulator possesses spontaneous polarization of 1.6μC∕cm2 and a coercive electric field of 50kV∕cm. After poling in an effort to obtain a large amount of accumulated charge, the field-effect mobilities of the hole and electron were 4.1×10−3 and 3.5×10−6cm2∕Vs, respectively. The on∕off ratio at VSG=±10V was 6×104 for the p type and 70 for the n type.