The evolution of properties of photonic crystal materials: From structural colors to multi-optical mode luminescence

With the advancement of optical materials, integrating multiple optical signals into a single material system can significantly enhance the functional diversity of optical devices, making it a current research hotspot and a key future development trend. This review systematically outlines the expansion of optical modalities in photonic crystals (PCs), with a focus on their evolution from traditional single structural colors to the integration of multiple luminescent characteristics toward multi-functionalization. First, we introduce the incorporation of fluorescent materials into conventional PCs to create fluorescent PCs, exploring how photonic structures modulate fluorescence emission to achieve enhanced luminescence and polarized light emission. Second, the development of room-temperature phosphorescent (RTP) materials and PCs has been constrained by their poor compatibility, stemming from differences in preparation methods and photophysical mechanisms. Accordingly, we focus on the design strategies for RTP photonic crystals. Additionally, RTP PCs integrating multiple optical signals enable synergistic interactions between specific optical signals. This review systematically investigates the regulatory patterns and mechanisms by which structured light originating from PCs modulates their own RTP luminescence. Finally, addressing current challenges such as fabrication bottlenecks, limited optical interaction capabilities, and restricted color expression, the review outlines future development directions and potential breakthroughs in this field.