Nanodomains key to high-performance solar cells: Cambridge

A study from the University of Cambridge examined how A-site cations influence nanodomains in lead halide perovskites. Researchers applied X-ray scattering, neutron spectroscopy, photoluminescence microscopy, and machine-learning simulations. The results showed that nanoscale structures differ based on cation choice. Methylammonium-based perovskites formed dense, anisotropic nanodomains with out-of-phase octahedral tilting. Formamidinium-based systems developed sparse, isotropic, spherical nanodomains with in-phase tilting. Both materials appeared cubic on average despite these local differences. Sparse, isotropic nanodomains reduced electronic dynamic disorder in formamidinium-based perovskites. This improved their optoelectronic response and device performance. The study linked nanoscale structure to macroscopic properties and showed how cation selection can control material behaviour for better device applications.