The article explores the high-performance capabilities of hybrid halide perovskite solar cells, focusing on the materials chemistry and physics of the bulk perovskite. The authors highlight the importance of optoelectronic properties, structural and compositional flexibility, and the spontaneous electric polarization exhibited by hybrid perovskites. They suggest that the presence of ferroelectric domains can enhance photovoltaic performance by aiding the separation of photoexcited electron-hole pairs and reducing recombination. The combination of a high dielectric constant and low effective mass promotes Wannier-Mott exciton separation and effective ionization of donor and acceptor defects. The photoferroelectric effect, where the internal electric field generated by the polar organic cation can be exploited in nanostructured films to increase the open-circuit voltage, is also discussed. The article provides insights into the key materials properties that contribute to the photovoltaic performance of organometallic perovskites and suggests ways to modify these properties through the choice of organic cations.The article explores the high-performance capabilities of hybrid halide perovskite solar cells, focusing on the materials chemistry and physics of the bulk perovskite. The authors highlight the importance of optoelectronic properties, structural and compositional flexibility, and the spontaneous electric polarization exhibited by hybrid perovskites. They suggest that the presence of ferroelectric domains can enhance photovoltaic performance by aiding the separation of photoexcited electron-hole pairs and reducing recombination. The combination of a high dielectric constant and low effective mass promotes Wannier-Mott exciton separation and effective ionization of donor and acceptor defects. The photoferroelectric effect, where the internal electric field generated by the polar organic cation can be exploited in nanostructured films to increase the open-circuit voltage, is also discussed. The article provides insights into the key materials properties that contribute to the photovoltaic performance of organometallic perovskites and suggests ways to modify these properties through the choice of organic cations.