High- k and low- k nanocomposite gate dielectrics for low voltage organic thin film transistors

Ce O2 -Si O2 nanocomposite films were used as the gate dielectrics in organic thin film transistors (OTFTs) with pentacene active semiconductor. Ce O2 -Si O2 composite films exhibited a high dielectric capacitance of 57 nF cm2 with exceptionally low leakage current. Good device characteristics were obtained with saturation at low operating voltages (∼2 V) and with a field effect mobility of 0.84 cm2 V-1 s-1, a threshold voltage of ∼0.25 V, an on/off current ratio of 103, and a subthreshold slope of 0.3 Vdecade, whereas the gate leakage current density is considerably lowered. These results should therefore increase the prospects of using OTFTs in low power applications such as portable devices.