Ink Engineering in Blade‐Coating Large‐Area Perovskite Solar Cells

To date, organic–inorganic hybrid perovskite solar cells (PSCs) have reached a certified efficiency of 25.7%, showing great potential in upscale industrial commercialization. However, a huge obstacle facing the industrialization of PSCs is the decreased efficiency and long-term stability when upscaling the device area. To overcome these issues, blade-coating methods have been developed to fabricate large-area PSCs due to their capability to deposit uniform large-area perovskite films. Ink engineering plays an important role in the blade-coating, especially for crystallinity and defect control. In this review, the blade-coating method to fabricate large-area perovskite films is first introduced. Then, the perovskite ink engineering for blade-coating PSCs is systematically summarized. Specifically, the effects of perovskite composition management and solvent engineering on perovskite film quality are discussed, and recent efforts in additive strategy to passivate perovskite defects are also summarized. Subsequently, recent advances in functional layer ink engineering and fully blade-coated PSCs are summarized. Moreover, the applications of blade-coating method in hole transporting material-free carbon-based PSCs are discussed. Finally, some suggestions and an outlook on this field are provided to help facilitate highly efficient and stable blade-coated PSCs.