Ferroelectrics are attractive due to their great application potential in information storage, optoelectronics, spintronics and sensing. As an important characteristic affecting semiconducting applications, the energy band structure is important for the development of light-emitting devices. Although it is a tremendous challenge to tune the bandgap in inorganic ferroelectric materials due to the strict requirement of structural symmetry for the fragile ferroelectricity, hybrid organic–inorganic perovskite (HOIP) ferroelectrics, which have a flexible structure, provide a new method to optimize the ferroelectric performance and bandgap. Based on the overview of methods for designing ferroelectrics, this Perspective systematically provides in-depth insight into the relationships between the structure–property and bandgap of HOIP ferroelectrics. In addition, we discussed the challenges and directions of HOIP ferroelectrics in semiconducting applications for the future.
