Dimensional control of low-dimensional perovskite hybrids for photovoltaics

Low-dimensional perovskite engineering offers a promising route to improve both power conversion efficiency and stability in perovskite photovoltaics, yet the mechanistic relationship between organic ligand design and structural control remains elusive. Here, we report a molecular design strategy for bis-imidazolium ligands that enables precise dimensional tuning of perovskite architectures, from zero-dimensional through parallel one-dimensional to bridged zero-dimensional configurations. Through systematic variation of terminal groups and inter-imidazole spacing, we achieve controlled growth of high-quality hybrid dimensional perovskite films with optimized crystallization kinetics and charge transport properties. This enables photovoltaic devices with a certified power conversion efficiency of 27.02% (laboratory 27.21%). Scaling this dimensional strategy enables the fabrication of 30×30 cm² perovskite solar modules, achieving a champion power conversion efficiency of 21.41% Moreover, unencapsulated devices retain 94.3% of their initial power conversion efficiency after 2000 hours of continuous operation at 60 °C (ISOS-L-2I), highlighting exceptional operational stability.