Effect of Mn doping on the electronic structure and absorption spectrum of Ba2SiO4:Eu2+ phosphor

The effect of Mn doping on the Ba2SiO4:Eu2+ phosphors is investigated in details. Comparing with the Ba2SiO4:Eu2+ phosphor, it is found that red-shift of the absorption spectrum in the wavelength of 220-470 nm appears for the Mn-doped Ba2SiO4:Eu2+ phosphor. The reason is that, smaller Mn2+ ions substitution on Ba2+ sites causes a shrinking of bond lengths, this leads to an increase of the crystal field strength, which results in splitting d-orbital of Eu2+ ions and the Eu2+ 5d level moving down ward in energy.