from the conferences organized by TANGER Ltd.
Organosilica binders are a promising way to interconnect various nanoparticles in printed coatings for photovoltaic cells and other applications. Post-deposition treatment of printed nanoparticle films with organosilica binders is required to remove the organic moieties and thus achieve the optimal optoelectronic properties of the resulting film. As a result, the polysiloxane binder is converted to almost fully amorphous silica and this process is called mineralization. Atmospheric pressure plasma operating in open air has proven to be the most promising method, as the operating temperature can be kept below 70 °C and the overall treatment time required is in order of minutes. These are significant advantages compared to alternative approaches like thermal sintering, where temperatures required are around 450 °C, or chemical or UV light treatment, where the treatment times extend into the order of hours. To better understand the underlying chemistry in the interaction of the ambient air plasma and the organosilica binder we performed an X-ray photoelectron spectroscopy (XPS) study on the plasma-treated films of silica binder, regularly used with titania nanoparticles. The detailed analysis of core-level spectra of C 1s, O 1s and Si 2p were used to observe the removal of methyl groups from the film and gradual transformation into amorphous SiO2. The scanning electron microscope revealed significant patterning of the surface by interaction with plasma after exposures longer than 16 seconds.
Keywords: Nanoparticle binder, organosilica, plasma mineralization, DCSBD, atmospheric pressure plasma© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.