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

Yttrium aluminum garnet Y 3 Al 5 O 12 (YAG):Er 3+,Tm 3+ 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 ∼30 nm. Photoluminescence (PL) spectra indicated the 2.7 μm emission of Er 3+ was remarkably enhanced via Tm 3+ 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.