Polymer thin-film transistor based on a high dielectric constant gate insulator

In this paper full polymer thin-film transistors (PTFTs) based on Poly (acrylonitrile) (PAN) as the gate dielectric and poly (2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene-vinylene) (MEH-PPV) as the semiconductor layer were investigated by using different channel width/length ratios. Relatively high dielectric constant of the polymer dielectric layer (6.27) can remarkably reduce the threshold voltage of the transistors to below -3V. Hole field-effect mobility of MEH-PPV of the PTFTs was about 4.8×10^-4cm²/Vs, and on/off current ratio was larger than 10², which was comparable with that of transistors with widely used Poly (4-vinyl phenol) (PVP) or SiO₂ as gate dielectrics.