Dual-gate pentacene organic field-effect transistors based on a nanoassembled SiO₂ nanoparticle thin film as the gate dielectric layer

In this paper, we report the fabrication of dual-gate organic field-effect transistors (OFETs) using self-assembled SiO₂ and thermal oxide as gate dielectric materials and pentacene as a semiconductor. The top dielectric layer was formed by the low-cost and low-temperature self-assembly with SiO₂ nanoparticles 45 nm in diameter. The fabricated dual-gate pentacene field-effect transistor (FET) has a threshold voltage of -2.2 V, a field-effect mobility of 0.1 cm²/V s, an I_on/off ratio of 3.8×10³, and a slope of 1.3 V/decade. Compared to a single gate OFET, dual-gate FET has better performance with higher drain output current at the relatively low operating voltage, larger field-effect mobility, and better channel controllability by separately adjusting two gate biases.