Electron-deficient 4-nitrophthalonitrile passivated efficient perovskite solar cells with efficiency exceeding 22%

We proved that electron-deficient 4-nitrophthalonitrile with σ–π accepting NO₂ and –CN can passivate the charged defects in perovskite solar cells, which achieve a power conversion efficiency (PCE) of 22.1% and improved stability.