Device Simulation Analysis of the Perovskite/Perovskite/Silicon Triple Junction Solar Cell Structure

In recent years, the development of perovskite/perovskite/silicon triple junction solar cells has received considerable attention, aiming to exceed the efficiency of perovskite/silicon dual junction solar cells. Various challenges must be addressed to reach these efficiencies and justify the additional complexity. This article outlines a simulation-based roadmap for improving the structure of these cells. It discusses critical issues and estimates potential improvements for perovskite/perovskite/silicon solar cells based on device architectures developed at Fraunhofer ISE and EPFL. The article describes potential challenges related to thickening the middle perovskite absorber to achieve current matching. It explains the observed losses in fill factor in the top cell with a high bandgap, which arise from an insufficient hole barrier caused by unfavorable valence-band alignment between the perovskite and the electron transport layer. These aspects are examined through numerical device simulations.