Recent Progress in Perovskite Materials Using Diammonium Organic Cations Toward Stable and Efficient Solar Cell Devices: Dion–Jacobson

Perovskite solar cells have been intensively studied recently due to their superb optoelectronic properties and rapidly increasing power conversion efficiency. However, perovskite solar cells with the AMX 3 structure as the light‐absorbing layer have a big stability problem. Multiple alternatives have been developed to ensure their stability, such as dimensional engineering (2D and 2D/3D), which consists of the incorporation of large organic cations into the perovskite structure. Research in dimensional engineering has been prevalent in the Ruddlesden–Popper phases. The presence of this large cation slows the decomposition and improves the stability of perovskites. Thus, new 2D perovskites are being studied based on Dion–Jacobson (DJ) phases, consisting of the addition of diammonium cations and leading to the formation of 2D and 2D/3D perovskites with better stability due to their hydrogen bonding on both sides. Moreover, 2D DJ perovskites offer the advantage of decreasing the gap between layers with higher contacts, which improves not only their optoelectronic properties, but also their charge transport properties. This article begins with an overview of the crystal structure and optoelectronic characteristics of 2D perovskites. Then, the progress achieved currently in using DJ‐phase perovskites in photovoltaic is assessed. Finally, the possible research routes for producing low‐dimensional perovskites are highlighted.