Screen printing of graphene-based nanocomposite inks for flexible organic integrated circuits

Graphene and multiwalled carbon nanotube (CNT) composites have been reported to be suitable conductive inks for screen-printing technology, which is a viable option for electrode patterning in organic integrated circuits. Considering the physical properties of the graphene–CNT composite ink, the optimized screen-printing conditions produce graphene–CNT patterns with good pattern fidelity. In addition, the use of a centrifugal mixer enables the composite to disperse graphene and CNT molecules well, stabilizing electrical conductance. In this study, these screen-printed graphene–CNT electrodes were applied to fabricate organic field-effect transistors (OFETs) on a glass substrate. The p- and n-type devices performed satisfactorily. Furthermore, screen printing of graphene–CNT enabled the integration of OFETs for fabricating complementary inverters, NAND, and NOR gates. We believe that the characterization of graphene–CNT inks can promote the advancement of organic integrated circuits beyond unit OFET devices based on an easy-to-use screen-printing technique.