Small Cations for Engineering 3D Hybrid Perovskites

Within the last 15 years, 3D hybrid perovskites made a breakthrough in the development of new semiconducting materials for diverse applications. This concept article addresses several critical questions central to the development and understanding of 3D hybrid perovskites. Specifically, it explores: (1) which organic cations are currently known to stabilize 3D perovskite structures; (2) the potential for discovering and utilizing new cations to support these structures; (3) the influence of the organic cation on physical, chemical, and optoelectronic properties of 3D hybrid perovskites; and (4) whether ongoing research should focus on the synthesis of novel 3D perovskites with alternative small organic cations. By examining these questions, this article aims to provide insights into the structural versatility, property optimization, and future directions for this rapidly evolving field, while also critically evaluating the feasibility and value of expanding the library of organic cations for 3D hybrid perovskite materials.