Blue-emitting SrB2O4:Eu2+ phosphor with high color purity for near-UV white light-emitting diodes

Abstract A blue-emitting SrB 2 O 4 :Eu 2+ phosphor with high color purity was synthesized by conventional high-temperature solid state reaction method. Its crystal structure, luminescence properties and concentration quenching mechanism were investigated. This phosphor can be effectively excited within the broad near ultraviolet wavelength region from 270 to 350 nm and feature a satisfactory blue-emitting performance. In particular, the color purity of the as-synthesized SrB 2 O 4 :Eu 2+ phosphor is much better than that of the blue emitting, commercial compound BaMgAl 10 O 7 :Eu 2+ . The emission peaks located at 448 nm, which can be attributed to the transitions of 4f 6 5d 1 to 4f 7 of Eu 2+ ions. It is shown that the 6.0 mol% doping concentration of Eu 2+ ions in SrB 2 O 4 :Eu 2+ phosphor is optimum, and that the concentration quenching occurs when Eu 2+ concentration is beyond 6.0 mol%. The physical mechanism of concentration quenching mechanism can be explained by the dipole–dipole interaction of Eu 2+ ions, and the critical transfer distance was determined to be 13.98 A. The present work suggests that the SrB 2 O 4 :Eu 2+ phosphor is a promising blue-emitting material for near-UV white light-emitting diodes.