Inkjet Printed Poly(3-hexylthiophene) Thin-Film Transistors: Effect of Self-Assembled Monolayer

Abstract

Organic thin film transistors (OTFTs) with bottom gate and top contact structure had been prepared by inkjet printing. It is found that the surface properties of the substrates have a great influence on the morphology of the inkjet printed droplet and film. An appropriate surface was vital to form a uniform semiconducting film by inkjet printing and also strongly improved the electric characteristics. When a bare SiO2 layer was applied, the best field-effect mobility of inkjet printed OTFT devices was only 2.37 × 10−3 cm2V−1s−1, with an on/off current ratio of 102. When the PETS treatment or the PTS treatment was applied on the SiO2 dielectric layer, the field-effect performances were substantially improved and the best field-effect mobility was enhanced to 8.07 × 10−3 cm−2V−1s−1 and 7.95 × 10−3 cm−2V−1s−1, respectively and with an on/off current ratio of 103.