Developing a robust recombination contact to realize monolithic perovskite tandems with industrially common p-type silicon solar cells

Although two-terminal perovskite-silicon tandem solar cells have rapidly increased in efficiency, they have only been demonstrated with n-type silicon, which currently constitutes less than 5% of the global photovoltaics market. In this paper, we realize the first two-terminal perovskite tandem with p-type silicon by developing a recombination contact that enables voltage addition without damaging either subcell. We find that silicon interband recombination contacts are limited by a SiO_x charge-extraction barrier, which forms during oxidative top-cell fabrication. A sputtered 30-nm indium tin oxide layer is found to protect the silicon cell surface from oxidation, while forming a recombination contact with the p-type nickel oxide hole transport layer for the perovskite top cell. Using this recombination contact we achieve voltage addition between the perovskite top cell and aluminum back-surface field p-type silicon bottom cell. We also find that minimizing moisture on the nickel oxide surface is important for achieving a stable open-circuit voltage under illumination. The recombination contact developed herein could play an important role in near-future developments.