| AVS 61st International Symposium & Exhibition | |
| Plasma Science and Technology | Friday Sessions |
| Session PS2-FrM |
| Session: | Plasma Surface Interactions II |
| Presenter: | Souvik Ghosh, Case Western Reserve University |
| Authors: | S. Ghosh, Case Western Reserve University R. Yang, Case Western Reserve University A.C. Barnes, Case Western Reserve University S. Rowan, Case Western Reserve University C.A. Zorman, Case Western Reserve University P.X.-L. Feng, Case Western Reserve University R.M. Sankaran, Case Western Reserve University |
| Correspondent: | Click to Email |
Such materials may be of interest for emerging applications in organic electronics, photovoltaics, and medical devices. However, few studies have assessed the electrical conductivity which is critical to these technologies.
Here, we show that polymer films loaded with metal cations can be converted to electrically conductive surfaces by an atmospheric-pressure plasma process. [4] Films of polyacrylic acid are loaded with Ag cations by solution processing and doctor’s blade casting technique. The films are exposed to an atmospheric-pressure microplasma jet so that by scanning the plasma across the surface, microscale patterns with ~300 μm line width are produced. Reduction to crystalline metal is confirmed by X-ray diffraction. Characterization of the films by scanning electron microscopy and energy dispersive spectroscopy reveals that plasma exposure results in nucleation and growth of aggregated Ag nanoparticles. Additionally, cross sectional images show that the formation of Ag is limited to near the surface (~5 μm). Electrical characterization of the films shows that the patterns are highly conductive with a bulk resistivity of ~1 mΩ-cm. To understand the mechanism for reduction, we compared our process with UV irradiation, heating, and laser treatment. None of these approaches produced similar reduction, crystallinity, or conductivity. We hypothesize an electrodiffusion model whereby Ag cations diffuse in the polymer film only in the presence of the plasma which creates an electric field through the film. This results in an enrichment of Ag cations at the surface. Reduction by the plasma then leads to a near-surface metallized layer. Thus, highly conductive surface patterns are generated from relatively low loadings of metal . References: [1] J. J. et al., Langmuir 22, 11388 (2006). [2] S. W. Lee et al., Adv. Func. Mater.21, 2155 (2011). [3] S. W. Lee et al., Macromolecules45, 8201 (2012). [4] S. Ghosh et al., ACS Appl. Mater. Interfaces 6, 3099 (2014).