title: Inkjet Printed Circuits on Flexible and Rigid Substrates Based on Ambipolar Carbon Nanotubes with High Operational Stability.
abstract: Inkjet printed ambipolar transistors and circuits with high operational stability are demonstrated on flexible and rigid substrates employing semiconducting single-walled carbon nanotubes (SWCNTs). All patterns, which include electrodes, semiconductors, and vias, are realized by inkjet printing without the use of rigid physical masks and photolithography. An Al2O3 layer deposited on devices by atomic layer deposition (ALD) transforms p-type SWCNT thin-film transistors (TFTs) into ambipolar SWCNT TFTs and encapsulates them effectively. The ambipolar SWCNT TFTs have balanced electron and hole mobilities, which facilitates their use in multicomponent circuits. For example, a variety of logic gates and ring oscillators are demonstrated based on the ambipolar TFTs. The three-stage ring oscillator operates continuously for longer than 80 h under ambient conditions with only slight deviations in oscillation frequency. The successful demonstration of ambipolar devices by inkjet printing will enable a new class of circuits that utilize n-channel, p-channel, and ambipolar circuit components.
authors.affiliation: Microelectronics Research Center, The University of Texas at Austin , Austin, Texas 78758, United States.
authors.forename: Bongjun
authors.initials: B
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering and Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Geier
authors.affiliation: Department of Materials Science and Engineering and Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Hersam
authors.affiliation: Microelectronics Research Center, The University of Texas at Austin , Austin, Texas 78758, United States.
authors.forename: Ananth
authors.initials: A
authors.lastname: Dodabalapur
keywords: air stable operation; ambipolar circuit; atomic layer deposition; carbon nanotube; flexible electronics; printed electronics; thin-film transistor