The conventional photonic crystals (PCs) are usually prepared by the self-assembly of silica or polystyrene particles. However, their applications are limited significantly due to the lack of the functions of the building blocks. Here, a new kind of photo-luminescent photonic crystals (PLPCs) with brilliant PL and structural colors were prepared by the self-assembly of dye-doped silica particles. The PL and structural colors of PCs can be well-controlled by altering the species of dyes and the size of the particles, respectively. Based on these advantages, PLPC patterns with encrypted information were fabricated through the combination of PLPCs and PCs with similar structural colors but diverse PL colors. These patterns can reversibly hide and display the encrypted information under sunlight and UV illumination, respectively. This work paves a new way for constructing functional PCs and will promote their applications in anti-counterfeiting, smart labels, and optical devices.

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Molecular junctions with similar backbones, tunable chemical structures and controllable length are critical for systematic study of the structure–functionality relationships of their charge transport behavior. Taking advantage of the feasibility...

The model for the effective electromagnetic coefficients is established. The influence of the volume ratio of the outer layer and the inner on the absorption and the characteristic impedance is discussed. The microstructure of the coated absorbent is designed. Sol-gel method is used to prepare the coated radar absorbent. It is shown by the theoretical and experimental results that the absorbing ability of the coated magnetic absorbent has be improved greatly, and the absorbing band below -8 dB is about 9 GHz.

Based on the mutual interaction between the electromagnetic wave and pigment, the theoretical model is formulated. The influence of various factors, such as the size of the pigment, the volume ratio of pigment, and the optical constants, on the spectral reflective properties is systematically analyzed. Experiment has been performed to testify the theoretical model. The theoretical design for the spectral reflective properties of the stealth coating is further proposed.