Particle decoration enables solution-processed perovskite integration with fully-textured silicon for efficient tandem solar cells

Perovskite/silicon tandem solar cells can exceed Shockley-Queisser limit, but achieving complete coverage of 2-4 μm pyramids on industrial fully-textured silicon with solution-processed perovskite film remains challenging. We address this issue by spray-coating alumina particles onto fully-textured silicon, creating a super-hydrophilic rough surface that both enhances wet film coverage and provides guided nucleation sites. Although super-hydrophilic effect enhances wetting, it alone is insufficient to achieve complete coverage of pyramids by perovskite film. Beyond enhanced wetting, alumina particles promote uniform nucleation at particle-decorated sites across pyramids by lowering nucleation barrier and suppressing valley-preferred nucleation, which enables near-conformal deposition of perovskite film on pyramids. Additionally, alumina particles reduce nonradiative recombination and extend carrier lifetimes. Using this approach, we achieve a efficiency of 32.74% for perovskite/silicon tandem solar cells with one-step solution-processed perovskite on fully-textured silicon. This strategy offers a pathway for seamless integration of perovskite and silicon photovoltaics into high-performance tandem devices.