Tuning of multicolor emissions in glass ceramics containing γ-Ga2O3 and β-YF3nanocrystals

Abstract

A novel tunable emitting glass ceramic containing β-YF₃:Tm³⁺ and γ-Ga₂O₃:Mn²⁺ nanocrystals was fabricated based on a strategy of “dopant isolation”. X-ray diffraction and transmission electron microscopy indicated two nanophases, i.e. β-YF₃ and γ-Ga₂O₃, embedded in the glass matrix. Analyses on the crystal structure, photoluminescence spectra, time-resolved emission spectra, and decay curves revealed the incorporation of Mn²⁺ ions into the tetrahedral sites of γ-Ga₂O₃, while the absorption spectrum and Judd–Ofelt calculations demonstrated the selective doping of Tm³⁺ ions in the nine-fold coordinated sites of β-YF₃. Evidently, energy transfer between Tm³⁺ and Mn²⁺ is suppressed due to their spatial separation, which enables the tuning of the emissive color from blue, green, yellow and red to white by varying the dopant species and concentrations in the material. Such a strategy would provide a convenient route to integrate separate single-color-emitting components into unity for near-UV excited white-light LEDs and great opportunities for fabricating various nanophase embedded glass ceramics doped with distinct active ions.