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Tm3+/Er3+/Yb3+co-doped oxyfluoride tellurite and germanate glasses have been synthesized by conventional melting method. Intense up-conversion (UC) luminescence emissions were simultaneously observed under 980 nm excitation at room temperature in two glasses. The possible UC mechanisms are discussed and estimated. However, in the studied Tm3+/Er3+/Yb3+co-doped oxyfluoride glasses, tellurite glass showed weaker UC emissions than germanate glass, which is inconsistent with the prediction from the difference of maximum phonon energy between oxyfluoride tellurite and germanate glasses. Absorption spectrum and Raman spectroscopy were employed to investigate the origin of the difference in UC luminescence in two glasses. Our results confirm that, besides the maximum phonon energy, the phonon density of host glasses is another important factor in determining the UC efficiency.

Upconversion (UC) luminescence photonic band gap materials Tb3+-Yb3+ co-doped phosphate inverse opal photonic crystals were prepared by a self-assembly technique in combination with a sol-gel method. The effect of photonic band gap on UC luminescence was investigated in inverse opals. Effective suppression of the UC luminescence was inspected if the photonic band gap overlapped with the emission band of Tb3+ ions.

A novel blue phosphor based on phosphate host matrix, MgAl(PO4)O doped with Eu2+ was prepared by solid state reaction. The phosphor invariably emits blue luminescence with a peak wavelength at around 450 nm under ultraviolet excitation. The excitation spectrum showed that the phosphor can be efficiently excited by UV-visible light from 250 nm to 420 nm, which is coupled well with the emission of UV LED (350-410 nm). The results indicated that this novel phosphor may become the candidate of blue radiation-converting phosphor for white light emitting diodes in the further.