Metal-free crystalline silicon solar cells in module

Solar cells interconnection with multiple wires enables the module integration of metal-free silicon heterojunction (SHJ) solar cells. The electrical contact occurs between the transparent conductive oxide (TCO) of the SHJ cell and the low melting point alloy coated on the wires. First proof-of-concept bifacial modules are presented. The module efficiency drop between standard SHJ silver screen-printed cells and metal-free SHJ cell is only 0.5% abs. This drop is related to the high contact resistance at the non-yet optimized TCO/wire interface, higher than typical TCO/silver finger contact resistance.