Laser‐Enabled Nanopinholes for Silicon Solar Cells with Polycrystalline Si/SiOx Passivating Contacts

Monocrystalline Si (c-Si)-based photovoltaic devices created with passivating contacts basedon nonconductive dielectric layers, such as thick (>1.7 nm) silicon oxide, silicon oxynitride, or transition metal oxides, require some method to create conductive pathways for charge-carrier transport. These methods can range from the thermal breakup of oxides to wet chemistries that etch nanopores in the dielectric. In this work, we demonstrate a laser-based method to create conductive pinholes via selective localized melting of the tips of pyramids on randomly textured c-Si surfaces. This method of creating pinholes results in a minimal loss of surface passivation (<3 fA/cm2 increase in J0) while enabling contact resistivities of <15 mΩ·cm2.