Recent Advances in Colloidal Photonic Crystal-Based Anti-Counterfeiting Materials

Abstract

Colloidal photonic crystal (PC)-based anti-counterfeiting materials have been widely studied due to their inimitable structural colors and tunable photonic band gaps (PBGs) as well as their convenient identification methods. In this review, we summarize recent developments of colloidal PCs in the field of anti-counterfeiting from aspects of security strategies, design, and fabrication principles, and identification means. Firstly, an overview of the strategies for constructing PC anti-counterfeiting materials composed of variable color PC patterns, invisible PC prints, and several other PC anti-counterfeiting materials is presented. Then, the synthesis methods, working principles, security level, and specific identification means of these three types of PC materials are discussed in detail. Finally, the summary of strengths and challenges, as well as development prospects in the attractive research field, are presented.