Solution-processed 2D perovskites are increasingly used in the fabrication of photodetectors. A new article by Liu and colleagues (Matter, 2019) demonstrates a surface tension-controlled method for the synthesis of inch-sized 2D perovskite single crystals and investigates the anisotropy of 2D perovskites for fabrication of high-performance planar photodetectors. Solution-processed 2D perovskites are increasingly used in the fabrication of photodetectors. A new article by Liu and colleagues (Matter, 2019) demonstrates a surface tension-controlled method for the synthesis of inch-sized 2D perovskite single crystals and investigates the anisotropy of 2D perovskites for fabrication of high-performance planar photodetectors.