The upconversion (UC) luminescence and color tunable properties of Tb3+ ions were investigated by steady spectral under 980 LD excitation in the Cao.15ZrO.8501.85:Yb,Tb inverse opals fabricated by the self-assembly technique in combination with a sol-gel method. The inhibition of UC emission was inspected if the Tb3+ UC emission band was in the regions of the photonic bandgap, while enhancement of the UC emission occurred if the UC emission band located at the edge of the bandgap. Color modification of the UC emission was successfully obtained by the suppression or enhancement effect of the photonic band gap on the UC emission.
The up-conversion of Er3+/yb3+ co-doped transparent glass-ceramics 50SiO2-10A1F3-5TiO2-30BaF2-4LaF3-0.5ErF3-0.5YbF3 containing Ba2LaF7 nanocrystals under the changing of heat treatment temperature and time were investigated. The Ba2LaF7 nanocrystals precipitated from the glass matrix was confirmed by X-ray diffraction (XRD). The structural investigation carried out by XRD and trans- mission electron microscopy (TEM) evidenced the formation of cubic Ba2LaF7 nanocrystals with crystal size of about 14 nm. Comparing with the samples before heat treatment, the high efficiency up-conversion emission of Er3+/Yb3+ co-doped samples was observed in the glass-ceramics under 980 nm laser diode excitation. The increase in red emission intensity bands was stronger than the green bands when the crystal size increased. The mechanism for the up-conversion process in the glass-ceramics and the reasons for the increase of Er3+/yb3+ co-doped up-conversion intensity after heat treatment were discussed.