New Metallization Scheme for Interdigitated back Contact Silicon Heterojunction Solar Cells

This study reports on a new contact scheme for Silicon Heterojunction (Si-HJ) solar cells having Interdigitated Back Contacts (IBC). This new geometry with two metallization levels is used to avoid any electrical shading above the emitter and Back Surface Field (BSF) busbars. IBC Si-HJ solar cells with bi-level metallization are here compared experimentally to standard devices having a single-level contact scheme. Relative increases of 2% in Fill Factor (FF) and 8% in short circuit current density (Jsc) have been obtained with this optimized contact geometry on medium area solar cells (5x5cm2). Moreover, this technology can be used to increase the number of busbars on large area solar cells and therefore reduce series resistance effects.