title: Printed, sub-3V digital circuits on plastic from aqueous carbon nanotube inks.
abstract: Printing electronic components on plastic foils with functional liquid inks is an attractive approach for achieving flexible and low-cost circuitry for applications such as bendable displays and large-area sensors. The challenges for printed electronics, however, include characteristically slow switching frequencies and associated high supply voltages, which together impede widespread application. Combining printable high-capacitance dielectrics with printable high-mobility semiconductors could potentially solve these problems. Here we demonstrate fast, flexible digital circuits based on semiconducting carbon nanotube (CNT) networks and high-capacitance ion gel gate dielectrics, which were patterned by jet printing of liquid inks. Ion gel-gated CNT thin-film transistors (TFTs) with 50 microm channel lengths display ambipolar transport with electron and hole mobilities >20 cm(2)/V.s; these devices form the basis of printed inverters, NAND gates, and ring oscillators on both polyimide and SiO(2) substrates. Five-stage ring oscillators achieve frequencies >2 kHz at supply voltages of 2.5 V, corresponding to stage delay times of 50 micros. This performance represents a substantial improvement for printed circuitry fabricated from functional liquid inks.
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455, USA.
authors.forename: Mingjing
authors.initials: M
authors.lastname: Ha
authors.forename: Yu
authors.initials: Y
authors.lastname: Xia
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Green
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Mike J
authors.initials: MJ
authors.lastname: Renn
authors.forename: Chris H
authors.initials: CH
authors.lastname: Kim
authors.forename: Mark C
authors.initials: MC
authors.lastname: Hersam
authors.forename: C Daniel
authors.initials: CD
authors.lastname: Frisbie