Preparation And Luminescent Properties Of Rare Earth Ions Doped Fluorosilicate Glass Ceramics

A series of transparent luminescent glass ceramics containing SrF₂:Yb³⁺nanocrystals were prepared and their microstructure and luminescence properties areinvestigated. As Yb³⁺ in the glass ceramics could be enriched into the precipitatedSrF₂ nanocrystalline phase, which provide much lower phonon vibration energy thanthe glass matrix. As a result, intense co-operative upconversion luminescence of theglass ceramics were observed, both in the glass and glass ceramics when pumpingwith 980 nm LD, which was contributed to two-photon upconversion.The glass ceramics containing SrF₂:Yb³⁺,Er³⁺ nanocrystals were prepared andtheir quantum cutting luminescence behaviors were investigated. XRD and TEMresults showed that SrF₂ nanocrystals containing Yb³⁺/Er³⁺ distributed homogenouslyin glass ceramics. Luminescence spectra revealed that efficient energy transfer fromEr³⁺ to Yb³⁺, including the quantum cutting luminescence, existed in the glassceramics with the excitation at the UV-Vis Er³⁺ excitation peak wavelength. With theincrease of heat treated temperature, the glass ceramics exhibited the increase of 977nm luminescence intensity and lifetime.The glass ceramics containing SrF₂:Yb³⁺,Tm³⁺ nanocrystals were prepared andtheir microstructure and luminescence properties were investigated. In the glassceramics, around 10-20 nm SrF₂ nanocrystals were embedded uniformly in the glassmatrix. The Yb³⁺ and Tm³⁺ could be enriched into the precipitated SrF₂nanocrystalline phase in the glass ceramics, which provide much lower phononvibration energy than the glass matrix. As a result, the upconversion luminescence ofthe glass ceramics were enhanced by orders of magnitude, compared to that of theglass when pumping with 980 nm LD. The upconversion mechanisms wer mainly dueto Yb³⁺-Yb³⁺ cooperative upconversion, Yb³⁺-Tm³⁺ cross relaxations andTm³⁺-Tm³⁺ cross relaxations.