Fast process to decorate silver nanoparticles on carbon nanomaterials for preparing high-performance flexible transparent conductive films.

This work demonstrates a fast process to decorate silver (Ag) nanoparticles onto the functionalized few-walled carbon nanotubes (f-FWCNTs) and graphene nanosheets (f-GNs). The Ag-coated carbon nanomaterials were used as fillers, which mixed with poly(3,4-ethylenedioxythiophene)-poly(4-stryensulfonate) (PEDOT:PSS) for preparing high optoelectronic performances of flexible transparent conductive films (TCFs). The Ag nanoparticles with a particle size of approximate 5 nm were uniformly distributed on the surfaces of the f-FWCNTs (Ag@f-FWCNTs) and the f-GNs (Ag@f-GNs). The Ag ions play the role of electron acceptors during the reduction process, which increases the hole concentrations in PEDOT:PSS, f-FWCNTs, and f-GNs, therefore enhancing the electrical conductivity of the TCFs. Additionally, the Schottky barrier was decreased because of the increase of work functions of the carbon fillers caused by Ag decoration. The X-ray diffraction spectrum of Ag@f-GNs depicts the formations of the face-centered cubic Ag nanoparticles, and the peak of the (002) graphene plane slightly shifted to the lower frequency, indicating that the f-GN interlayer was intercalated with Ag ions or Ag nanoparticles. When the mixture of 2.0 wt % Ag@f-FWCNTs and 8.0 wt % Ag@f-GNs containing PEDOT:PSS dispersant was coated onto a poly(ethylene terephthalate) (PET) substrate, outstanding optoelectronic properties with a sheet resistance of 50.3 Ω/sq and a transmittance of 79.73% at a wavelength of 550 nm were achieved.