Metal Perovskite Halides (Fluoride, Chloride, Bromide, and Iodide) and Their Composites

Metal halide perovskites (MHPs) are an emerging class of materials with a fundamental structure based on the ABX 3 formula, analogous to metal oxide perovskites (ABO 3 ). MHPs have advantages over other types of materials due to flexibility in halide selection (F − , Cl − , Br − , and I − ), enabling the formation of diverse compositions with tunable optoelectronic properties. Unlike traditional oxide perovskites, MHPs exhibit high photovoltaic efficiency, making them promising candidates for solar cells, light-emitting diodes, and energy storage applications. The advantages of MHPs include tunable bandgaps, strong light absorption, high ionic mobility, and ease of fabrication through sol-gel, hydrothermal, microwave, and hot injection methods. Integration of MHPs in composite with materials like graphene oxide, MXene, and polymers further enhances their performance. This chapter provides an in-depth discussion on the recent development in MHPs and their composites, their chemistry, properties, and applications, making it valuable for academic, research, and industrial professionals.