Low voltage pentacene thin film transistors employing a self-grown metal-oxide as a gate dielectric

We propose a method to implement low voltage operation of pentacene thin film transistors (TFTs). Ultrathin Al2O3 was used as a gate dielectric and was directly grown on a preexisting Al gate by an oxygen plasma process. Thus, an extra patterning process for the gate dielectric is not necessary, and the overall fabrication process is thereby simplified. The organic TFTs operated at low voltage, producing 1.5μA at VGS=−2V and VDS=−1.5V, with a threshold voltage of −1.18±0.027V, a mobility of 0.12±0.015cm2∕Vs, and an on/off current ratio of 8.76±5.3×103.