Research progress of single crystal perovskite growth

Abstract

Single crystals are attracting increasing interest in photovoltaics research due to their superior material properties. In contrast to polycrystalline thin films that currently dominate high-efficiency device development, single-crystal perovskites, characterized by their grain-boundary-free bulk structure, exhibit a potential ability superior to polycrystalline perovskites. This review summarizes key advancements in the field, hinging on the successful synthesis of micron-thick single-crystal sheets via several preparation techniques such as the Bridgman growth method. Through evolution from the initial MAPbI₃ system to mixed-cation compositions (e.g., FA_0.95Cs_0.05PbI₃), coupled with interface engineering and surface passivation strategies, the power conversion efficiency (PCE) of PSSCs has achieved a remarkable leap from single digits to a record 25.8%, accompanied by enhanced operational stability. However, to realize their commercial viability, several critical challenges must be addressed. As we illustrated in this review, further challenges, for instance, reducing the crystal thickness to below 10 micrometers, ensuring robust mechanical and electrical contact between the single crystal and charge transport layers, and developing scalable fabrication techniques for large-area and uniform single crystals, are worthy of further investigations. Despite these hurdles, the considerable potential demonstrated by PSSCs lays a solid foundation for their emergence as a next-generation photovoltaic technology boasting both high performance and exceptional durability.