Novel mask-less plating metallization route for bifacial silicon heterojunction solar cells

The proof of concept of a novel metallization route for bifacial silicon heterojunction (SHJ) solar cells by selective plating - i.e. organic mask-free, is demonstrated by a first lab scale solar cell (i=15.5%). A patterned metal-seed is inkjet-printed or deposited by PVD on a PVD-Al layer covering the ITO layer. The copper electroplating process is investigated considering different electrolytes and plating settings in order to selectively cover the metal-seed and not the PVD Al layer. As well a processing chemistry to etch the PVD-Al layer without affecting the ITO and the electroplated contact is presented.