Aligned 𝛼-FAPbI3 (100) Facet toward Efficient Photovoltaic Operation

The disorder and disarray of 𝛼-FAPbI3 (100), (110), and (111) facets at the primary charge injection barrier (SnO2/perovskite interface) significantly hinder interfacial crystallography investigations into carrier extraction and transport processes, thereby limiting improvements in device performance. Here, we aligned the growth and arrangement of 𝛼-FAPbI3 facets at the SnO2/perovskite interface by incorporating carboxylic acid molecules. The highly uniform distribution of (100) perovskite facets at the SnO2/perovskite interface is successfully achieved, leading to a substantial improvement in carrier transport and overall device performance. Consequently, the fabricated photovoltaic device delivered an impressive power conversion efficiency (PCE) as high as 26.18% (25.49% certified). After stable operation for over 2400 hours under maximum power point tracking, the device still maintained over 91% of its initial efficiency, showcasing outstanding stability.