Mobile Oxygen Capture Enhances Photothermal Stability of Perovskite Solar Cells Under ISOS Protocols

Abstract Stability testing protocols from the International Summit on Organic and Hybrid Solar Cell Stability (ISOS) are essential for standardizing studies on the photothermally operational stability of perovskite solar cells (PSCs). Under photothermal conditions, the migration of oxygen from SnO 2 layer induces cationic dehydrogenation at the A‐site of the perovskite, accelerating degradation to PbI 2 . This leads to the formation of photoinduced I 2 and Pb 0 defects, significantly compromising long‐term stability. In this study, ordonezite (ZnSb 2 O 6‐x ) as a multifunctional electron transport layer (ETL) that captures migrating oxygen atoms at the SnO 2 /perovskite interface is introduced, effectively preventing degradation of the buried interface. Additionally, the lattice match between ZnSb 2 O 6‐x and perovskite facilitates well‐ordered perovskite film growth. As a result, PSCs featuring ZnSb 2 O 6‐x ETLs achieved a high power conversion efficiency of 25.02% and retained 90.62% of their initial performance after 1000 h under the ISOS‐D‐2 protocol. Furthermore, devices demonstrated remarkable thermal stability, maintaining 83.69% of their original performance after 800 h of maximum power point tracking at 85 °C, meeting the stringent ISOS‐L‐2 protocol requirements.