Low-voltage organic thin film transistors with hydrophobic aluminum nitride film as gate insulator

This paper reports on the low-voltage (<5 V) pentacene-based organic thin film transistors (OTFTs) with a hydrophobic aluminum nitride (AlN) gate-dielectric. In this work, a thin (about 50 nm), smooth (roughness about 0.18 nm) and low-leakage AlN gate dielectric is obtained and characterized. The AlN film is hydrophobic and the surface free energy is similar to the organic or the polymer films. The demonstrated AlN–OTFTs were operated at a low-voltage (3–5 V). A low-threshold voltage (−2 V) and an extremely low-subthreshold swing (∼170 mV/dec) were also obtained. Under low-voltage operating conditions, the on/off current ratio exceeded 106, and the field effect mobility was mobility was 1.67 cm2/V s.