Effect of surface treatment on the conductive adhesive interconnection of flexible solar cells

The effects of plasma-treatment on the contact quality of the molybdenum back contact of flexible solar cells interconnected with isotropic conductive adhesives have been studied. The influence of the surface treatment on surface properties like roughness, contact angles and surface energies have been measured and flow characteristics have been analyzed. The contact resistances and microsections have been studied. Pre-treatment might help to increase the spreading of the freshly applied conductive adhesive on a surface, but also enhances the thickness of the polymer layer at the interface. Because the contact geometry largely depends on the dispensing parameter, it was also found that a highly thixotropic adhesive does not show significantly better wetting behavior on the treated surface. The samples without preliminary plasma treatment show better contact resistance in that case.