Screen-Printed Metallization Concepts for Large-Area Back-Contact Back-Junction Silicon Solar Cells

In this study, we investigate three screen-printed metallization concepts for back-contact back-junction silicon solar cells with an edge length of 156 mm: 1) a busbar-less concept with periodically interrupted contact fingers for wire-based interconnection; 2) a single-layer concept with printed busbars and periodically interrupted contact fingers; and 3) a multilayer concept consisting of continuous contact fingers, an insulation layer, and busbar metallization. A comprehensive simulation study is presented for all investigated metallization concepts, yielding their respective performance loss mechanisms. The multilayer approach is found to provide superior conversion efficiencies η, compared with the single-layer approach. For the wire-based concept, we show that contact finger interruptions up to a width of 1 mm have no significant negative impact on cell performance (Δη <; 0.1%abs). Furthermore, peel force measurements on test structures between soldered cell interconnectors and screen-printed metallization are discussed for the multilayer and the wire-based concept. Successful proof of principles with peel forces exceeding 1 N/mm are demonstrated for both investigated metallization concepts.