Abstract Perovskite solar cells (PSCs) with an n‐i‐p structure have achieved remarkable power conversion efficiencies over the past decade; however, their long‐term stability remains a key challenge for real‐world deployment. In particular, the hole‐transporting layer (HTL)/perovskite interface plays a critical role in governing device performance and durability, as it directly impacts charge extraction and influences both chemical and mechanical stability under stress. Here, we present an enantiomeric‐engineering strategy to address the stability issue at the HTL/perovskite interface based on low‐dimensional, Br‐rich, chiral perovskites. We show that the R ‐ and S ‐enantiomers, when integrated into a heterochiral perovskite, form a densely packed benzene‐ring configuration that provides superior resistance to environmental degradation and device operational stress compared with the single‐enantiomer counterpart. Moreover, the low‐D Br‐based chiral perovskites prefer to bind to the defect sites at the grain boundaries of the perovskite absorber, thus reducing the number of active centers that can initiate degradation, especially under moisture, light, and heat. The champion power conversion efficiency (PCE) reaches 25.79% for heterochiral perovskite interfaces, compared to 25.51% for homochiral and 24.92% for pristine counterparts. Moreover, PSCs with heterochiral perovskite interfaces demonstrate an extended operational stability lifetime with a T 95 over 600 h under maximum‐power point tracking (MPPT), surpassing T 95 (310 h) of homochiral and T 95 (195 h) of pristine controls. This work highlights the potential of using enantiomeric chiral perovskite design to tailor interfacial structure and stability, contributing to the development of durable and efficient perovskite solar cells.
Yu et al. (Mon,) studied this question.