Multifunctional Additives Suppressed Phase Segregation of Wide–Bandgap Perovskites for Semitransparent Solar Cells

, thereby regulating perovskite crystallization, reducing defect density, and suppressing phase segregation. This strategy enables semi-transparent perovskite solar cells to deliver a power conversion efficiency of 19.7% with enhanced operational stability, retaining over 85% of the initial efficiency after 1000 hr of maximum power point tracking. When integrated into two terminal monolithic perovskite-silicon tandem solar cells, the DMECl strategy further enables an efficiency of 29%.