Additive jet printing of polymer thin-film transistors

Organic thin-film transistors were fabricated by direct patterning of solution-processable semiconductors consisting of either poly(9,9′-dioctyl-fluorene-co-bithiophene) or a regioregular poly(thiophene). Acoustic ink-jet printing was used to deposit the polymeric semiconductor onto patterned metal source-drain contacts. Printed and spin coated transistors performed identically. The regioregular poly(thiophene) exhibited a mobility of 0.1 cm2 V–1 s−1, on-off current ratios of ∼106 and low threshold voltage.