Doping and de-doping of carbon nanotube transparent conducting films by dispersant and chemical treatment

Abstract

Single-walled carbon nanotubes (SWCNTs) dispersed with Nafion in a solvent mixture containing de-ionized water and 1-propanol (bisolvent) were sprayed on a poly(ethylene terephthalate) substrate to fabricate flexible transparent conducting films (TCFs). Different SWCNT-to-Nafion ratios were used to optimize the film performance of transparence and sheet resistance. The TCFs were then immersed in nitric acid. These steps resulted in p-type doping due to the presence of Nafion in the SWCNT network and de-doping (removal of doping effect) by the acid treatment. X-Ray photoelectron and Raman spectroscopy confirmed that the de-doping effect occurred with the partial removal of Nafion from the nanotube surface by the nitric acid treatment, which improved the film conductivity by a factor of $4 with negligible change in transmittance.

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

“…This also shows a temperature irreversible I-V character, like the water-washed CNT films. This phenomenon may due to the de-doping effect with evaporation and decomposition of the adsorbates during the heating process [25]. Fig.…”

“…Spray coating can easily generate large area films on suitable substrates. The sheet resistance and transmittance of CNT films rely on the coating thickness and all decrease with the increase of film thickness [16,25,26]. The film sheet resistance of CNT films on polyethylene terephthalate (PET, with high transmittance in visible region) substrate and it stability were usually studied at room temperature (RT), and seldomly studied at high temperature.…”

The effect of thermal treatment on polymer-dispersed single-walled carbon nanotube transparent conductive film

“…Recently, various approaches have been investigated to enhance the conductivity of SWCNT TCFs through post treatment. Acid treatment with HNO 3 [26] and SOCl 2 [27] have been widely used but the instability of the electrical properties due to the de-doping effect, even under ambient conditions and reported as a serious drawback in many applications [22,28,29].…”

Direct electron transfer and electrocatalysis of hemoglobin immobilized on graphene–Pt nanocomposite

“…The C1s peak was fitted into five components related to: graphite C@C at 284.8 eV, hydrocarbon C-C at 285.7 eV, C-O bond at 286.6 eV, a carbonyl group (C@O) near 288.2 eV, and an carboxylate group (COO-) near 290.2 eV[33][34][35], and the absorbance peaks of oxygen functionalities are weak. The result indicates that most of the epoxide and hydroxyl functional group on the graphene oxide sheet were removed.…”