Stability Improvement of Organic Thin-Film Transistors Using Stacked Gate Dielectrics

Poly-3-hexylthiophene organic thin-film transistors (OTFTs) were fabricated with different kinds of stacked gate dielectrics, which exhibit an individual effective trap behavior. The transistor fabricated with a stacked gate dielectric in a donor-like trap behavior exhibits a significant current hysteresis loop, a large threshold voltage shift, and subthreshold swing changes during operation in the dark and under illumination. The device performance is improved using a stacked gate dielectric with acceptor-like traps. The mechanisms of OTFTs with an acceptor-like trap dielectric and a donor-like dielectric are discussed.