An alkaline earth aluminate-based SrAl2O4:Eu2+ phosphor was prepared by solid-state reaction at 1300-1500 oC in a reduced atmosphere. The prepared SrAl2O4:Eu2+ phosphors were found to exhibit a monoclinic phase in crystal structure and any secondary phase formation by the Eu2+ addition was not detected. Symmetric single broad band photoluminescence (PL) emission spectra centered at ~514 nm due to the 4f65d1→4f7 (8S7/2) transition wsere obtained from the SrAl2O4:Eu2+ phosphors, which indicates the doped Eu2+ ions occupied only one type of site in the SrAl2O4 lattice and the formation of one corresponding Eu2+ emission luminescent center. PL emission intensity showed a strong dependence on the Eu2+ doping concentration and the strongest emission was observed for the 7 mol% Eu2+-doped SrAl2O4 phosphor. Dynamic light scattering (DLS) and field-effect scanning electron microscopy (FE-SEM) characterization revealed that the 7 mol% Eu2+-doped SrAl2O4 phosphor particles have an irregularly round shape and an average particle size of ~4 μm.

Keywords: SrAl2O4:Eu2+ phosphors, Solid-state reaction, Green phosphors, Photoluminescence properties