Mixed-cation mixed-halide perovskite solar cells have been characterized in DC at different temperatures (from −20 °C up to 50 °C) and the time evolution of the device efficiency has been assessed ...using different degradation protocols (indoors and outdoors). The completely planar p-i-n structure is ITO/CuNiO
x
/PTAA/CsFAPbIBr/PCBM/PEI/Ag. Pristine current-voltage characteristics barely show hysteresis, at any temperature. Open circuit voltage decreases with temperature at a rate of −1.5 mV °C
−1
, and the obtained PCE temperature coefficient is lower than −0.001% K
−1
, which is an outstanding value for this emerging photovoltaic technology. Cells have been degraded under different protocols: indoors using different light/dark cycles and outdoors in a high temperature and high irradiation location. Cells show no significant decrease of the efficiency after more than 350 h of indoor light cycling and the estimated
T
80
obtained for the sample degraded outdoors under high irradiation and high temperature conditions is ∼15 days.
Ideality factor
vs.
temperature obtained from the dependence of open circuit voltage on the irradiation level (inset).
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 (MAPbI3), electron transporting layer (6,6‐phenyl‐C61‐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 SnO2 layer to protect the MAPbI3 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 MAPbI3‐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.
Herein, a unique SnO2 layer to protect the underlaying layers from damage of the sputtered transparent electrode is developed. Moreover, a high‐near‐infrared transparent perovskite solar cell using cerium‐doped indium oxide is prepared, achieving a record power conversion efficiency (PCE) of 17.23%. As a result, a four‐terminal perovskite/silicon tandem solar cell with a PCE of 26.14% is obtained.
