Recent advances in photonic crystals for anti-counterfeit labels

In recent years, photonic crystals(PCs) have become increasingly widely used in anti-counterfeiting because of their advantages of being difficult to replicate, easy to identify, and highly functional. This review summarizes the recent developments in PCs in the field of anti-counterfeiting. Firstly, the preparation methods and characteristics of inorganic and organic materials are reviewed. Subsequently, the self-assembly methods are discussed, including solvent evaporation methods, externally induced methods, and coating methods. Then, the PCs patterning methods and anti-counterfeiting modes of PCs-based anti-counterfeit labels are outlined. Finally, the better application prospects and challenges faced by PCs in the field of anti-counterfeiting are presented.