Screen Printing as a Scalable and Low-Cost Approach for Rigid and Flexible Thin-Film Transistors Using Separated Carbon Nanotubes

Abstract

Semiconducting single-wall carbon nanotubes are very promising materials in printed electronics due to their excellent mechanical and electrical property, outstanding printability, and great potential for flexible electronics. Nonetheless, developing scalable and low-cost approaches for manufacturing fully printed high-performance single-wall carbon nanotube thin-film transistors remains a major challenge. Here we report that screen printing, which is a simple, scalable, and cost-effective technique, can be used to produce both rigid and flexible thin-film transistors using separated single-wall carbon nanotubes. Our fully printed top-gated nanotube thin-film transistors on rigid and flexible substrates exhibit decent performance, with mobility up to 7.67 cm2 V(-1) s(-1), on/off ratio of 10(4)∼10(5), minimal hysteresis, and low operation voltage (<10 V). In addition, outstanding mechanical flexibility of printed nanotube thin-film transistors (bent with radius of curvature down to 3 mm) and driving capability for organic light-emitting diode have been demonstrated. Given the high performance of the fully screen-printed single-wall carbon nanotube thin-film transistors, we believe screen printing stands as a low-cost, scalable, and reliable approach to manufacture high-performance nanotube thin-film transistors for application in display electronics. Moreover, this technique may be used to fabricate thin-film transistors based on other materials for large-area flexible macroelectronics, and low-cost display electronics.

Surface effects on network formation of conjugated polymer wrapped semiconducting single walled carbon nanotubes and thin film transistor performance

“…The 9 mg/L solution gave the highest network density (39 tubes/lm 2 ) and mobility (8.1 ± 2.1 cm 2 /Vs) on PLL coated SiO 2 . This mobility is very similar to that observed by Zhou and co-workers in which screen printed TFTs using polymer sorted tubes (IsoSol-S100) were coated onto a PLL treated SiO 2 and PET substrate [24]. Comparatively, the 9 mg/L solutions yielded 68 tubes/lm 2 and a mobility of 18 ± 1.6 cm 2 /Vs on bare SiO 2 .…”

“…Liu et al has recently reported that hydrophilic and partially negatively charged surfaces are favorable to adhere SWCNTs wrapped with poly[(9,9-dioctylfluore ne-2,7-diyl)-co-(1,4-benzo-2,1,3-thiadiazole)], whereby hydrogen bonding between silanol groups on the SiO 2 surface and the benzothiadiazole moiety provided strong adhesion and the use of positively charged adhesion layers provided no added benefit [23]. Cao et al recently reported the use of PLL coated SiO 2 and PET in the fabrication of screen printed TFTs using poly(di-alkylfluorene) wrapped SWCNTs, yet they did not elaborate on the benefits of using the adhesion layer [24]. Device performance variability will be compounded by variation in print resolution and registration, hence it is important to gain further understanding on the interplay between surface energy, network morphology (uniformity, density) and device performance variability (mobility, on/off ratio, on-current) in order to optimize deposition conditions and mitigate printing limitations.…”

All‐Carbon Thin‐Film Transistors as a Step Towards Flexible and Transparent Electronics

“…[29][30][31][32][33] Besides their use as transparent electrodes, carbon-based thin films, especially the CNT thin film, are good candidates for the semiconducting channel of TFTs, and many impressive research achievements have been reported to demonstrate wide range of possible uses for carbon-based flexible electronics. [34][35][36][37][38][39][40][41][42][43][44][45][46][47][48] It is recognized that carbon is a unique element that can be used in both the electrode and the channel for the fabrication of all-carbon TFTs and ICs for extremely flexible and transparent electronics.…”

Raman microscopy mapping for the purity assessment of chirality enriched carbon nanotube networks in thin-film transistors

“…The advantage of using networks of sc-SWCNTs over aligned nanotubes [52][53][54][55] for the active channel in TFTs is the favorable trade-off between targeted performance and ease of fabrication [56][57][58]. Such TFTs will be useful in low-cost display drivers and logic-circuit elements fabricated using scalable deposition techniques such as dip-coating and ink-jet or gravure printing [59][60][61][62][63][64][65][66]. This work bridges the gap between separation methods that yield high-purity sc-SWCNTs and the available characterization tools for purity assessment, thus providing a framework for device design that considers TFT channel scaling with SWCNT density and purity.…”