Bimolecular Hetero‐Spatial Co‐Passivation Enables Efficient MA‐Free Wide‐Bandgap Perovskites for All‐Perovskite Tandem Solar Cells

ABSTRACT All‐perovskite tandem solar cells (AP‐TSCs) offer the potential to surpass the Shockley–Queisser (S–Q) limit of single‐junction perovskite solar cells (PSCs). Nevertheless, the wide‐bandgap (WBG) sub‐cells suffer from severe open‐circuit voltage ( V OC ) losses induced by surface defects and energy‐level mismatch at the WBG perovskite/C 60 interface. Herein, we implemented a bimolecular passivation strategy by achieving hetero‐spatial distribution of piperazinium bromide (PipBr) and 3‐(methylthio) propylamine hydrobromide (3MTPABr) in the WBG perovskite surface layer. Pip + facilitates a reconstruction of the perovskite surface to form an anchored‐gradient passivation region, while 3MTPA + constructs…

• NN
  National Natural Science Foundation of China

  Awards: 62304158, 52162028, 52262033
• NS
  Natural Science Foundation of Hubei Province

  Award: 2025AFB088
• NS
  Natural Science Foundation of Jiangxi Province

  Awards: 20232ACB204011, 20232ACB214004
• MD
  Major Discipline Academic and Technical Leaders Training Program of Jiangxi Province

  Award: 20225BCJ23018