The effects of Eu ions and Eu:Dy ratio on the luminescence properties off blue–green BaAlxOy:Eu2+,Dy3+ nano-phosphors

Novel Blue–green emitting BaAlxOy:Eu2+,Dy3+ phosphors were synthesized by the solution-combustion method. The influence of various parameters (dopants, co-dopants) on the morphological, structural and photoluminescence (PL) properties of the phosphor were investigated by various techniques. Phosphor nanocrystallites with high brightness were obtained without significantly changing the crystalline structure of the host. The EDS spectra of all samples show the expected chemical components in the phosphors. The XRD spectra displayed a clear indication of the formation of the expected hexagonal crystalline phase for the nanopowders with sizes of the particles in the nanorange. In the excitation spectra of BaAlxOy:Eu2+,Dy3+ phosphors, by monitoring 500 nm, the charge transfer bands (CTB) of Eu3+–O in the short UV region (240 nm) and broad band maximum at 340 nm, attributed to host excitation band can be observed, respectively. The emission spectra display the characteristic blue–green emission at around 500 nm of Eu2+ ions, ascribed to the 5d-4f transition of Eu2+ ions, and the optimal doping concentration is 1 mol%.

► BaAlxOy:Eu2+,Dy3+ nanoparticles with an average particle size of 40–80 nm were synthesized.
► The variations of Eu ions have no effect on the crystalline structure.
► The variations of Eu:Dy molar ratios hardly have effects on the emission peak position.
► The luminescent intensity and the density of traps increased with Eu ions and Eu:Dy molar ratios respectively.