Featuring Semitransparent p–i–n Perovskite Solar Cells for High‐Efficiency Four‐Terminal/Silicon Tandem Solar Cells

Two issues need to be resolved when fabricating p–i–n semitransparent perovskite solar cells (ST‐PVSCs) for four‐terminal (4 T) perovskite/silicon tandem solar cells: 1) damage to the underlying absorber (MAPbI 3 ), electron transporting layer ([6,6]‐phenyl‐C 61 ‐butyric acid methyl ester, PCBM), and work function (WF) modifier (polyethylenimine, PEI), resulting from the harsh sputtering conditions for the transparent electrodes (TEs) and 2) low average near‐infrared transmittance (ANT) of TEs. Herein, a unique SnO 2 layer to protect the MAPbI 3 and PCBM layers is developed and functions as a WF modifier for a new TE (cerium‐doped indium oxide, ICO), which exhibits an excellent ANT of 86.7% in the range of 800−1200 nm. Moreover, a MAPbI 3 ‐based p–i–n ST‐PVSC is prepared, achieving an excellent power conversion efficiency (PCE) of 17.23%. When it is placed over the Si solar cell, a 4 T tandem solar cell with a PCE of 26.14% is obtained.