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.

Chirality‐Enriched Carbon Nanotubes for Next‐Generation Computing

“…This ambipolarity enabled complementarylike ICs including a NAND gate, a NOR gate, and a three-stage ring oscillator (RO). [61] The RO structure operated continuously for 83 h with minimal performance variation [61] and allowed the sensing of polar vapors (e.g., acetone), [62] demonstrating the high stability and functionality of this inkjet printing scheme. Although most inkjet-printed SWCNT TFTs have channel lengths larger than 10 µm due to limitations in printing resolution, the fabrication of a fully inkjet-printed TFT with a submicrometer channel length has also been achieved.…”

Assembly and Electronic Applications of Colloidal Nanomaterials

“…[21,43,338] Alternatively, SWCNT networks can be deposited by dip coating, where the assembly is further facilitated by electrostatic interactions between charged surfactant-wrapped SWCNTs and amine-modified surfaces ( Figure 6B), [34,209,339] or by van der Waals or hydrophobic interactions between conducting-polymer-wrapped SWCNTs and chemically modified dielectric substrates. [257,258,340,341] The SWCNT density needs to be beyond the percolation threshold to form an electrically continuous network between the source and drain electrodes, [342] but should not be too large to reduce gate modulation due to screening effects from the excess SWCNTs in the network. [257,258,340,341] The SWCNT density needs to be beyond the percolation threshold to form an electrically continuous network between the source and drain electrodes, [342] but should not be too large to reduce gate modulation due to screening effects from the excess SWCNTs in the network.…”

“…[154,207] Patterns of SWCNT random networks can also be aerosol-jet or inkjet printed. [257,258,340,341] The SWCNT density needs to be beyond the percolation threshold to form an electrically continuous network between the source and drain electrodes, [342] but should not be too large to reduce gate modulation due to screening effects from the excess SWCNTs in the network. The innate trade-off between field-effect mobility and on/off ratio often requires a meticulous optimization of SWCNT densities to achieve desirable device performance.…”

P‐77: Area‐Selective Atomic Layer Deposition Using Inkjet‐printed Fluorocarbon Patterns as Mask Layers

“…Inkjet printing process as an alternate patterning method is introduced to pattern polymer thin films for AS-ALD [9,15]. Inkjet printing process has been transformed into sophisticated device manufacturing methods for low-cost, large-area, and flexible electronics [16]. One of the main advantages is the ability to precisely position material on a substrate using computer control to produce structures without the need for masks [17].…”