Fabrication and evaluation of adhesion enhanced flexible carbon nanotube transparent conducting films

Abstract

Single-walled carbon nanotubes (SWCNTs) were dispersed in water with the help of a combination of surfactants to achieve a high concentration SWCNT ink. Transparent conducting films (TCFs) were fabricated through a rod-coating method using the SWCNT ink. The addition of binders (polyacrylic acid or carboxymethyl cellulose) greatly enhanced the adhesion of SWCNT films to substrates and the cohesion between CNTs, which produced a uniform film of SWCNTs by preventing damage during the post-treatment process. The thickness of SWCNT films is controlled by the amount of SWCNTs in the solution and the diameter of the wire used. To test the film adhesion, Scotcht tape was used to detach some loosely bound SWCNTs. Then the SWCNT films were further post-treated with nitric acid to improve the conductivity. The addition of polyacrylic acid to the SWCNT dispersion improved the film adhesion obviously without decreasing its electrical conductivity. This rod-coating method demonstrates great potential for the scalable fabrication of flexible SWCNT-TCFs.

Zn/Al complex-SWCNT ink for transparent and conducting homogeneous films by scalable bar coating method

“…3,4 Thus, Single Wall Carbon Nanotube (SWCNT), having excellent opto-electrical and mechanical properties, 5,6 which is superior to ITO, have attracted attention of scientists and engineers to make use of this unique material in the TCF fabrication. [7][8][9][10][11] Despite many attempts for the application of SWCNT in the transparent electronics, preparation of high quality TCF is still challenging. Thus, Y. Zhou et al reported the stable doping of SWCNT film by CuI with the sheet resistance of 55-65 ohm/sq at the transmittance of 80%.…”

“…16 Organic dispersants such as surfactants have been widely used to disperse SWCNTs in aqueous media; Sodium Dodecylbenzene Sulfonate (SDBS) and Sodium Dodecyl Sulfate (SDS) have been used for the film fabrication up to date. 7,[17][18][19] However, the application of surfactants is not suitable for the TCF fabrication because of its non-transparency and non-conductivity in a dry state. This implicates that the surfactants need to be removed from the SWCNT film in order to maintain the high electrical conductivity and optical transparency of the SWCNT film.…”

“…Several studies have shown that the surfactants are removable with concentrated HNO 3 treatment for 30 or 60 min. 7,[17][18][19] Indeed, the film with sheet resistance of 70 ohm/sq at the transmittance of 80% has been obtained after removal of SDS. 17 Reducing of the removal time as well as concentration of HNO 3 for the film treatment should improve efficiency in the scalable TCF fabrication technology.…”

Enhanced Adhesion of Polydimethylsiloxane Using an Interlocked Finger Structure

“…However, its poor adhesion remains a major problem in actual applications. For example, stretchable and flexible electronics that heavily rely on PDMS have recently been developed, but its poor adhesion is a serious problem when assembling this flexible substrate into devices …”

Temperature and voltage dependent current–voltage behavior of single-walled carbon nanotube transparent conducting films

“…TCFs fabricated using single-walled CNTs (SWCNTs) are widely explored in numerous applications such as electron field emitters [7], supercapacitors [8], thin-film transistors [9], organic photovoltaics [10], and organic light emitting diodes (OLEDs) [11,12]. TCFs have been fabricated using CNTs by various methods, such as vacuum filtration [13,14], spin coating [15], spray coating [16,17], dip coating [18], inkjet printing [19,20], gel coating [21], Mayer rod coating [22,23] and self-assembly methods [24]. Spray coating can easily generate large area films on suitable substrates.…”