Characterization of Recombination Properties and Contact Resistivity of Laser-Processed Localized Contacts from Doped Silicon Nanoparticle Ink and Spin-On Dopants

An increase in market share of very high-efficiency solar cell concepts, such as interdigitated back contact (IBC) solar cells, is typically limited by their high cost due to complex and expensive processing sequences. Implementation of localized laser-doped contacts is a promising route to reduce fabrication costs while maintaining the high-efficiency potential of such solar cell concepts, also offering the potential to use cheaper, upgraded metallurgical silicon which may otherwise be vulnerable to degradation when exposed to traditional high-temperature processing. In this work, we introduce novel test structures and perform numerical simulations to accurately determine the contact properties, namely, the recombination parameter J_0,c down to values of 300 fA cm^-2 and contact resistivity ρ_c down to values of 1 × 10^-4 Ω cm². We analyze the performance of 30 μm × 30 μm-sized laser-doped localized contacts prepared using boron and phosphorus spin-on dopants and phosphorus-doped silicon nanoparticle ink. The laser-doped contacts characterized in this work allow for 23.7% efficient IBC solar cells as we demonstrate by numerical.