Research Progress on Rare Earth Materials for Reflecting NIR

In response to the limitations of traditional near-infrared (NIR) reflective materials, which exhibit monotonous coloration and induce object heating due to NIR radiation, rare earth elements have emerged as a research focus for developing high-reflectivity, multicolored, and environmentally friendly reflective materials due to their unique optical properties. This study highlights mainly expounds the synthesis methods, crystal structure control strategies, performance characteristics, and application status of rare earth composite reflective materials. The principal preparation techniques include the solid-phase methods, sol-gel methods, and self-propagating combustion. Among these, the sol-gel method is widely utilized due to its molecular-level homogeneity and structural controllability. Through doping with rare earth ions, the energy band structure and lattice distortion of materials can be effectively modulated to achieve high reflectivity (up to 98%) within the NIR band wavelength range (700 nm~2500 nm) as well as color diversity. Furthermore, this study outlines future research prospects for rare earth composite reflective materials.