A General Strategy for Ultralong Phosphorescent Photonic Crystals, Achieving Thermal Sensitive, Tri‐State Optically Compensated Gels

• Published in: Advanced functional materials 2024-11, Vol.34 (48), p.n/a
• Main Authors: Wang, Changxing, Ning, Yayun, Wen, Xiaoxiang, Yue, Yifan, Xie, Yuechi, Zhang, Jinxia, Li, Jianing, Yang, Sen, Lu, Xuegang
• Format: Article
• Language: English
• Subjects: Atomic energy levels; Chemical bonds; Chemiluminescence; Covalent bonds; Crystal defects; Gels; general strategy; Morphology; multifunctional application; Nanospheres; Optical properties; optically compensated gels; Phosphorescence; phosphorescent photonic crystals; Photoluminescence; Photonic crystals; Self-assembly; Silicon dioxide; Smart materials; Surface defects; Windows (apertures)
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202408632

Integration of photoluminescence (PL), especially the long‐lived room‐temperature phosphorescence (RTP), into periodic submicron structures to build multi‐optical morphology photonic crystals (PCs) is a trend for future optical devices but has proven extremely challenging. Here, an emerging general strategy for fabricating three‐optical morphology (tri‐state) SiO2‐based PCs by calcining monodisperse SiO2 nanospheres with carbon dots (CDs) encapsulated inside is reported. The resulting phosphorescent SiO2 nanospheres are unaffected by the type of surface defects or heteroatom doped in CDs, but rely on C─Si covalent bonds to stabilize the excited triplet state (T1). The high degree of integration of chemiluminescent molecules and physical unit arrays offers the possibility of PCs with RTP emission in various physical morphologies. The assembled tri‐state PCs exhibit vivid structural colors, blue PL and green RTP under different light stimulation. Additionally, an intelligent thermal‐responsive optically tri‐state PC gel is successfully fabricated by self‐assembly of colloidal particles in suspensions. The optical signals (including structural color, transmittance, PL, and RTP) of the gels exhibit complementary properties regulated by temperature in the reflection and transmission modes. The general strategy and multifunctionality of these tri‐state PCs and gels open new avenues for applications in decorative coatings, tri‐morphology recyclable smart windows, and information encryption. A general approach for synthesizing monodisperse CDs@SiO2 nanospheres with ultralong phosphorescent has been developed. The high degree of integration of the chemiluminescence unit and physical unit results in the tri‐state PCs and PC gels with switchable optical morphologies. Additionally, the smart thermal‐responsive tri‐state PC gels show temperature‐controlled optical compensation properties (including structural color, transmittance, PL, and RTP).