Crystallization Modulation and Holistic Passivation Enables Efficient Two-Terminal Perovskite/CuIn(Ga)Se2 Tandem Solar Cells

• Integrating perovskite solar cells onto irregular rough CuIn(Ga)Se2 (CIGS) surfaces remains a challenge; new strategy was explored to develop monolithic perovskite/CIGS tandem solar cell by manipulating the crystallization of perovskite. • Surface reconstruction and field-effect passivation are developed synergistically to issue complex interface relationship between perovskite and C60. • The champion power conversion efficiency (PCE) of 24.6% realized, providing significant commercial opportunities for all thin-film-based perovskite/CIGS tandem cells. • D-homoserine lactone hydrochloride improves coverage and passivates bulk defects by modulating PVK crystal growth, while 2-TEAI/DMF and LiF reduce interface recombination.