All-Polymer Complementary Logic on Plastic With Micrometer-Scale Laser-Ablated Channels

Maskless fabrication of polymer field-effect transistors (FETs), especially on flexible substrates, offers a more sustainable production scheme for large-area integrated circuits. To be practically relevant, scalable fabrication approaches granting micrometer-scale patterning resolution are necessary. To this end, parallelizable direct-writing techniques, such as materials printing and laser patterning, have been proposed as a promising approach. Yet, the possibility of fabricating circuits with such an approach has not been reported. Here, we demonstrate the fabrication of p- and n-type FETs based on printed conjugated polymers on plastic foil by combining inkjet printing and femtosecond laser ablation. We utilize Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as the printed electrodes, independently optimized for hole (p-type) and electron (n-type) injection. The flexibility of our direct-writing process in defining the geometrical features of FETs is exploited to match complementary transistors and achieve balanced complementary logic inverters. The robustness of the inverters and compatibility of the proposed fabrication scheme on plastic is reported with the realization of a proof-of-principle all-polymer three-stage complementary ring oscillator (RO) operating down to 5 V.