A novel design of donor-acceptor polymer semiconductors for printed electronics: application to transistors and gas sensors

Jet printing of π-conjugated polymers synthesized through simple solution processes has been considered promising for the direct patterning of organic semiconductors on large-area substrates. However, it is still challenging to achieve direct patterns of high-performance polymer semiconductors through the electrohydrodynamic jet printing because of the relatively low solubilities of donor–acceptor π-conjugated polymers having high charge carrier mobilities and operation stabilities. A novel synthesis is proposed to obtain donor–acceptor π-conjugated polymer semiconductors suitable for printed electronics with exhibiting high performance of hole transport properties. The backbones and side chains of the donor–acceptor π-conjugated polymers are fully engineered to (1) achieve balanced jetting conditions and (2) provide time to induce the intermolecular self-assembly during the continuous printing. The printed polymers have similar morphologies and molecular orderings to those of spin-coated semiconductor films, which provide high uniform electrical performances of organic field-effect transistors (OFETs) with a saturation mobility similar to those of the spin-coated films, up to 3.07 cm2 V–1 s–1. Furthermore, these high performances and operational stability suggests feasibility of the printed OFETs to be applied to ammonia gas sensors. Our study guides the designs of π-conjugated polymers suitable for large-area printing processes to contribute printed electronics.