2.7 μm Emission from Transparent Er3+,Tm3+ Codoped Yttrium Aluminum Garnet (Y3Al5O12) Nanocrystals-Tellurate Glass Composites by Novel Comelting Technology

Yttrium aluminum garnet Y3Al5O12 (YAG):Er3+,Tm3+ phosphor powders with preferable luminescent properties and nanocrystals with better morphology were synthesized by the solid-state reaction method and coprecipitation method, respectively. The composition and morphology were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), which showed that the nanocrystals were pseudomonodispersed with the particle size of similar to 30 nm. Photoluminescence (PL) spectra indicated the 2.7 mu m emission of Er3+ was remarkably enhanced via Tm3+ sensitization, and a novel circulatory energy transfer mechanism was proposed. A novel dehydration method was used to decrease the contents of the hydroxyl group (OH-) confirmed by photoluminescence spectra and Fourier transform infrared spectra (FTIR). YAG crystallites were introduced into tellurate glass and formed to glass composites with good optical performance. These nanocrystals-glass composites open a brand new field for the research of mid-infrared laser materials.