Printed, sub-3V digital circuits on plastic from aqueous carbon nanotube inks.
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.
Ha
Mingjing
M
Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455, USA.
Xia
Yu
Y
Green
Alexander A
AA
Zhang
Wei
W
Renn
Mike J
MJ
Kim
Chris H
CH
Hersam
Mark C
MC
Frisbie
C Daniel
CD