Synthesis and tunable emission studies of new up-converting Ba₂GdV₃O₁₁ nanopowders doped with Yb³⁺/Ln³⁺ (Ln³⁺ = Er³⁺, Ho³⁺, Tm³⁺)

Highlights: • Pure Ba₂GdV₃O₁₁ based phosphors were obtained by sol-gel Pechini method. • The first upconverting phosphor based on Ba₂GdV₃O₁₁ matrix has been synthesized. • Two-phonon upconversion phenomenon was confirmed. • Luminescence intensity and lifetime are dependent on annealing temperature. - Abstract: Nanopowders of Ba₂GdV₃O₁₁ were successfully synthesized using a sol-gel method. Luminescence upconversion properties in the obtained Ba₂GdV₃O₁₁ matrix doped with the Yb³⁺/Er³⁺, Yb³⁺/Ho³⁺ and Yb³⁺/Tm³⁺ ion pairs were investigated. Thermogravimetric analysis was necessary to set the optimal calcination temperature of the gel precursors and to form desired structure. Monoclinic structure and P21/a space group of products were defined based on X-ray diffraction analysis method and compared with an appropriate reference pattern. Morphology and the grain sizes of obtained nanophosphors were confirmed by transmission electron microscopy. The nanomaterials containing lanthanide ions in the structure show intense visible green, red and blue emission under infrared radiation, λ_exc = 985 nm, depending on the emitting Ln³⁺ ions used (Ln³⁺ = Er³⁺, Ho³⁺, Tm³⁺). Detailed spectroscopic analysis showed dependence of luminescence intensity and lifetime of the nanophosphor samples on calcination temperature.