Laser‐Enabled Nanopinholes for Silicon Solar Cells with Polycrystalline Si/SiO x 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/cm 2 increase in J 0 ) while enabling contact resistivities of <15 mΩ·cm 2 .