Fully roll-to-roll gravure printed carbon nanotube based flexible thin film transistor backplane on 100 m of poly(ethyleneterephtalate) (PET) web

Abstract

R2R gravure with two printing units with the overlay printing registration accuracy of ±20 μm is introduced to fabricate 20 × 20 TFTs backplane on 150 m of PET web. The resultants of fully printed TFT backplanes were characterized based on the concept to extract the scalability for manufacturing wall paper like sensor sheets. In this gravure system, silver nanoparticle based conductive ink, BaTiO3 based dielectric ink and single walled carbon nanotube based semiconducting ink were used for printing 20 × 20 TFT backplanes on 100 m of PET web. Rheological properties were optimized with the consideration of printing reliability and electrical properties of resulting TFTs. Mobility, transconductance, threshold voltage, and on-off current ratio of 20 × 20 printed TFT backplanes were analyzed for extracting the parameters to define the scalability factors for practical applications.