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).