Characterization of Localized Contacts

Abstract

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 J0,c down to values of 300 fA cm^-2 and contact resistivity ρc 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.