A pure and stable intermediate phase is key to growing aligned and vertically monolithic perovskite crystals for efficient PIN planar perovskite solar cells with high processibility and stability

A pure and stable intermediate phase can drastically facilitate the growth of a perovskite layer with aligned and vertically monolithic crystals on a NiO nanocrystal film, leading to a high PCE of ~18.4% also with significantly improved cell stability and processibility.183