Manipulation strategy of cation inhomogeneity in perovskite solar cells

• Mixed-cation perovskites achieve over 26% PCE but suffer from element and phase segregation that degrades device performance and stability. • Segregation occurs during fabrication and aging, influenced by precursor colloidal properties, crystallization kinetics, and processing conditions. • Understanding the mechanisms of inhomogeneity is crucial for developing nanoscale regulatory strategies to improve MCP quality. • Achieving uniform cation distribution and stable phases is essential for overcoming stability challenges in perovskite solar cells.