Enhancement of fluorescent properties of photonic crystals containing triplet-triplet annihilation upconversion materials via adjusting incident angles

摘要

AbstractA triplet–triplet annihilation upconversion luminescent (TTA-UCL) material of platinum(II)-octaethylporphyrin and 9,10-diphenylanthracene (PtDPA) was dispersed in the silica photonic crystal (PC) gaps to construct a hybrid fluorescent structure. The morphology, forbidden band effects and fluorescent properties were characterized by field emission scanning electron microscopy, Ultraviolet–Visible spectrophotometer and photoluminescence analysis, respectively. The results indicated that the fluorescent intensity of PtDPA detected from different angles was enhanced with the aid of PC structure and the emission intensity came to the strongest when the emission and excitation peaks of PtDPA were coincident with the forbidden bands of the PC structure. Crystal diffraction theory, finite-difference-time-domain method and plane wave expansion method were used to analyze the effect of incident angle on forbidden band effects of the PC film. The results showed that the forbidden band position of the PC moved from 571 to 400 nm when the incident angle changed from 0° to 75° gradually and split into two forbidden bands when the incident angle was larger than 45°. The adjustment of incident angle, thus, provided a convenient way to control the fluorescent properties of TTA-UCL materials coupled with PCs.