Perovskite tungstate Ba2La2ZnW2O12:Mn4+ phosphor: Synthesis, energy transfer and tunable emission

Ba₂La₂ZnW₂O₁₂:xMn⁴⁺ (BLZWO:xMn⁴⁺) (0 ≤ x ≤ 1.2 mol%) are prepared via the solid state reaction method under air conditions. The crystal phases and optical properties of all samples are investigated. The yellow emission of BLZWO is observed with the chromaticity coordinates (0.3940, 0.4389), and its emission spectrum covers the region from 380 to 810 nm owing to the W⁶⁺ - O²⁻ transition. When the excitation wavelength is 344 nm, BLZWO:xMn⁴⁺ show an adjustable photo-luminescence characteristic by altering the Mn⁴⁺ concentration owing to the energy transfer from [WO₆] group to Mn⁴⁺ ions. With excitation at 514 nm, BLZWO:xMn⁴⁺ only show red emission. The excitation spectrum of BLZWO:Mn⁴⁺ with peaks at 344 and 514 nm is in the region from 210 to 600 nm and its emission spectrum with peak at 704 nm are observed in the range of 625–800 nm. The lifetimes of BLZWO:xMn⁴⁺ reduce successively with adding Mn⁴⁺ concentration. The results are good for the basic research on luminescence characteristics of Mn⁴⁺ ion.