Low-temperature solution-processed alumina as gate dielectric for reducing the operating-voltage of organic field-effect transistors

We report a facile route for developing solution-processed Al2O3 film at low temperature (<180 °C) and its application in organic field-effect transistors (OFETs). Compared to OFETs using conventional SiO2 gate dielectric, the pentacene-based OFETs using Al2O3 thin film gate dielectric achieved comparable on-off drain current ratio (over 105), five times high field-effect mobility (∼2.7 cm2/Vs), threshold voltage of ∼−1.4 V and a greatly reduced operating voltage. The achieved low voltage operation can significantly reduce power consumption of OFETs. Furthermore, the low-temperature processing of the solution-processed Al2O3 film paves the way for fabricating organic electronic devices on flexible plastic substrates.