Analysis of (Ba,Ca,Sr)3MgSi2O8:Eu2+, Mn2+ phosphors for application in solid state lighting

The luminescence properties of Eu2+ and Mn2+ co-activated (Ba,Ca,Sr)3MgSi2O8 phosphors prepared by combustion synthesis were studied. Eu2+-activated (Ba,Ca,Sr)3MgSi2O8 has a broad blue emission band centered at 450–485 nm and Eu2+–Mn2+-activated (Ba,Ca,Sr)3MgSi2O8 exhibits a red emission around 620–703 nm, depending on the relative concentrations of Ba, Ca and Sr. The particle size of Eu2+ and Mn2+ co-activated (Ba,Ca)3MgSi2O8 ranges from 300 nm to 1 μm depending on the metal ion and are agglomerated due to post-synthesis, high temperature annealing. The green emission of Ba3MgSi2O8 originates from secondary phases (Ba2SiO4 and BaMgSiO4) confirmed by emission spectra and X-ray diffraction patterns. The secondary phases of Ba3MgSi2O8 are removed by the addition of Sr. The quantum efficiencies range from 45% to 70% under 400 nm excitation and the lifetime of red emission of Ba3MgSi2O8 decreases significantly with increasing temperature, which is 54% at 400 K of that at 80 K compared to that of blue emission (90% at 400 K of that at 80 K). -- highlights: • (Ba,Ca,Sr)3MgSi2O8:Eu2+, Mn2+ phosphors were prepared by a combustion synthesis method. • The emission spectra consist of broad blue-emission band and red-emission band. • The quantum efficiencies range between 45% and 70%, depending on the relative concentrations of Ba, Ca and Sr. • The secondary phases were eliminated by additions of Sr. • Lifetime of the red-emission decreases with increasing temperature, suggesting that these phosphors are not useful for solid state lighting applications