Hybrid sequential deposition process for fully textured perovskite/silicon tandem solar cells

Tandem solar cells that feature a high-bandgap perovskite cell on top of a lower bandgap silicon cell have the potential to reach efficiencies >30%. Here, we present a versatile hybrid deposition method that yields conformal perovskite cells directly on textured silicon bottom cells, a prerequisite to achieve highest photocurrents and hence efficiencies. Furthermore, this low-temperature evaporation/spin-coating 2-step method produces high-quality perovskite materials with different bandgaps, here varied in the range of 1.5 eV to 1.8 eV. This flexibility enables the fabrication of monolithic 2-terminal perovskite/textured Si tandems that feature high photocurrents of about 19.5 mA/cm ² .