Perovskite‐based solar cells currently are one of the most rapidly developing fields in solar photovoltaics. Chemical doping of perovskites with foreign atoms is a promising way to tailor material properties toward improving the performance and stability of solar cells. Herein, efficiency enhancement of planar MAPbI 3 perovskite solar cells by doping them with 0.1–5% Sr 2+ is discussed. A small amount (&lt;1%) of Sr 2+ added to the perovskite improves the V oc by ≈80 mV and consequently increases the power conversion efficiency (PCE) from 16.8% to 17.8%. Using transient photoluminescence, transient photocurrent, and time‐delayed collection field measurements, it is demonstrated that Sr 2+ additives reduce the trap density and increase the perovskite photoluminescence lifetime. However, reaching ≈1% concentration, Sr 2+ additives create additional carrier traps, which cause fast photoluminescence quenching and slow carrier recombination.

Suppression of Electron Trapping in MAPbI3 Perovskite by Sr2+ Doping