Metallization Fraction of Bifacial pSPEER Shingle Solar Cells
We present the investigation of metallization fraction of bifacial p-type silicon shingled passivated edge, emitter and rear (pSPEER) solar cells intended for shingled module integration. For the first group G1 (cell dimension: 23 mm x 148 mm), ten fabricated pSPEER cells, five each with a different busbar layout (single and double busbar), are utilized to measure the contact widths and calculate the metal coverage. Taking into account the shingling interconnected cell is overlapped, the reduced and therefore designated area metallization fraction is represented by the metal coverage of fingers and redundant line. The rear side metallization fraction for G1 for single and double busbar layouts based on designated area remain for both busbar types almost the same with around 25.9%. The same applies to the front side resulting in around 3.0%. For the second group G2 (cell dimension: 22 mm x 148 mm), five fabricated pSPEER cells are used. Metallization fraction for this group is lower than G1. The designated area metal coverage fraction on the rear side is 19.8%. The front side features metallization fraction of 2.8%. A complete overlap should be ensured precisely to avoid any variations in metallization fraction affecting the expected short-circuit current density values.