Monolithic 2-terminal perovskite silicon tandem solar cells

Perovskite silicon tandem solar cells promise lower levelized costs of electricity than single-junction silicon and perovskite solar cells. Achieving this goal requires high power conversion efficiencies >27% and stability for long device lifetime. [1] Furthermore, deposition on textured silicon would enable higher energy yields, [2] and lead-free perovskite absorbers would avoid acceptance issues due to environmental concerns. Applicability to different bottom solar cell concepts, such as PERC, TOPCon or SHJ, would further facilitate an evolutionary transition of the PV industry. [3] Our work addresses the above described challenges towards an industrialization of perovskite silicon tandem solar cells. We present tandem devices in the n‑i‑p and the p‑i‑n device architecture reaching 25.1% certified stabilized efficiency using the photo-stable bandgap adapted perovskite composition FA0.75Cs0.25Pb(I0.8Br0.2)3. We further show the deposition of the absorber on industry-relevant random pyramid silicon texture for improved light management and discuss possible options towards upscaling. Regarding lead-free perovskite absorbers, we present process-engineering of Cs2AgBiBr6 films and their application in solar cell devices.