Review of quasi-2D CaF₂materials: from synthesis and properties to device applications and future outlooks

The distinctive physical and chemical characteristics of calcium fluoride (CaF₂), including its cubic crystal structure, wide spectral transmittance, low refractive index, low dispersion, and high chemical stability, make it an essential component in the development of fluorine resources and exhibit indispensable key application values in a variety of industries, including semiconductor, optical, and medical. Systematic summaries of CaF₂'s preparation techniques, characteristics, and devices are still lacking in the academic community, though. The CaF₂summary is the main topic of this paper. It first explains in detail how CaF₂thin films, nano-calcium fluoride, and doped CaF₂are prepared. Additionally, a thorough overview of the application accomplishments of the four categories of electronic devices-energy and metallurgy, biomedicine, and environmental protection-as well as their classifications and combinations available. Finally, it conducts a forward-looking analysis of the future application scenarios and potential challenges of CaF₂, aiming to provide references and impetus for promoting subsequent research on CaF₂, CaF₂.