High-Performance Semiconducting Nanotube Inks: Progress and Prospects

Abstract

While the potential for high mobility printed semiconducting nanotube inks has been clear for over a decade, a myriad of scientific and technological issues has prevented commercialization and practical use. One of the most challenging scientific problems has been to understand the relationship between the pristine, individual nanotube mobility (known to be in the 10,000 cm(2)/V·s range) and the as-deposited random network mobility (recently demonstrated in the 100 cm(2)/V·s range). An additional significant scientific hurdle has been to understand, manage, and ultimately eliminate the effects of metallic nanotubes on the network performance, specifically the on/off ratio. Additional scientific progress is important in understanding the dependence of nanotube length, diameter, and density on device performance. Finally, the development of ink formulations that are of practical use in manufacturing is of paramount importance, especially with regard to drying time and uniformity, and ultimately, the issue of scalability and cost must be addressed. Many of these issues have recently been investigated from a phenomenological point of view, and a comprehensive understanding is beginning to emerge. In this paper, we present an overview of solution-based printed carbon nanotube devices and discuss long-term technology prospects. While significant technical challenges still remain, it is clear that the prospects for the use of nanotube ink in a myriad of systems is feasible given their unmatched mobility and compatibility with heterogeneous integration into a variety of applications in printed and flexible electronics.

Fundamental Performance Limits of Carbon Nanotube Thin-Film Transistors Achieved Using Hybrid Molecular Dielectrics

“…4b, the sub-threshold average on/off ratio ~10 5 . In contrast, as-grown CNTs produce low on/off ratios at significantly lower coverages due to the lower percolation threshold from the large fraction (30%) of long (~10 µm) metallic CNTs, 13,19 whereas monodisperse CNTs on low capacitance gate-dielectrics (e.g., 300 nm SiO 2 ) exhibit low on/off ratios, likely due to the onset of CNT-CNT screening at lower CNT densities. 18 Density-3 CNT TFTs were further characterized to investigate large-area uniformity and channel geometry effects.…”

“…12,13 First, high field-effect mobility (high transconductance) is necessary to achieve large voltage gain inverters in high speed circuits.…”

Nanoscale Charge Percolation Analysis in Polymer‐Sorted (7,5) Single‐Walled Carbon Nanotube Networks

“…However, most common synthesis methods produce a mixture of nanotube diameters and chiral angles, which typically results in only two-thirds of the as-synthesized SWNTs being semiconducting and the remaining one-third metallic. [14,15] This has a big impact on many opto-electronic applications, and especially in microelectronics, where the presence of metallic SWNTs, even at concentrations of few parts per thousand, could dramatically degrade device performances. [2,15] To overcome this issue, various post-synthetics sorting methods have been recently developed, such as gel chromatography, [16] density gradient ultracentrifugation [17] and polymer wrapping [18][19][20][21] .…”

Assisted sintering of silver nanoparticle inkjet ink on paper with active coatings

“…Among the many important applications for printed electronics are photovoltaic devices 1 , sensors 2 , displays 3 and radio-frequency identification (RFID) tags 4 . Many types of functional materials can be formulated into printable inks, including electrically conducting 5 , semiconducting 6 and insulating materials 7 , as well as materials with magnetic 8 , optical 9 , chemical 10 or biological 11 functions. When comparing printing methods, inkjet allows comparably small feature size, less than 40 µm on some substrates 12 .…”