Polarity and moisture induced trans-grain-boundaries 2D/3D coupling structure for flexible perovskite solar cells with high mechanical reliability and efficiency

Precise control of the growth of 2D perovskites on 3D perovskites to form “trans-grain boundaries” 2D/3D structure for the preparation of flexible perovskite solar cells with a certified PCE up to 22.1% and excellent mechanical stability.