Inkjet-printing for maskless separation of metal structures for back-contact silicon solar cells

A lean process route for the contact separation of back-contact solar cells is presented in this article. Inkjet-printing of an etchant is used for patterning Al- and NiV-layers with varying thickness deposited by means of physical vapor deposition (PVD). By adjusting the drop spacing of the droplets, the number of layers printed on top of each other, the temperature during printing and etching, and the etching time, the authors were able to fabricate a meander structure on a silicon wafer with an edge length of 156 mm that was coated with a 100 nm thick NiV-layer. Visual and electrical characterization was performed on test structures. The resistance between these separated structures was up to 1.5 M Omega and thus meets the requirement of a back-contact solar cell.