Surface termination passivation of imidazole-based diiodide enabling efficient inverted perovskite solar cells.

N -(3-aminopropyl)-imidazole diiodide (APDI) was introduced on the upper surface of the perovskite for the first time to modulate the terminal groups. The defect traps were suppressed by binding N cations from the APDI with Pb 2+ . Consequently, the optimum APDI-treated device achieved a PCE of 21.41% and exhibited excellent stability.