Tetraphosphorylated phthalocyanine–based self-assembled monolayer stabilizes perovskite photovoltaics

The self-assembled monolayer (SAM) has driven the rapid increase in the power conversion efficiency (PCE) of perovskite solar cells (PSCs). However, the operation stability of these PSCs under real conditions continues to be challenging. We developed an SAM based on phthalocyanine, which has a structurally robust framework with chemically stable bonds that enhance photostability. Tetraphosphorylation further enables the firmly locked phthalocyanine at the interface, which improves thermal stability, charge extraction, and assembly uniformity. Implementing this approach, a certified efficiency of 23.1% (stabilized 22.9%) for a perovskite solar module over a 20.3-square centimeter aperture area was achieved and the outdoor stability analysis was conducted following the ISOS-O-1 protocol, exhibiting no performance degradation throughout the entire outdoor aging test for 61 days, demonstrating reliable durability under real conditions.