Luminescence quenching by iron impurity in Eu2+, Dy3+ doped strontium aluminates.

The long afterglow phosphors SrAl₂O₄: Eu, Dy with different iron content have been prepared by nano-alumina coating process. The effect of crystal structure and luminescence properties of the phosphors by iron is investigated by XRD, luminescence spectra and afterglow curve. It is found that its crystal structure has no change, but luminescence properties have been quenched due to the existence of iron. By changing the iron content from 0. 001 mol to 0. 01 mol, the average luminescence intensity is decreased by 50%, which may be due to the Fe³⁺— O^2- energy transfer to infrared site. Simultaneously, the infrared luminescence in strontium aluminates by iron is observed for the first time. [ABSTRACT FROM AUTHOR]