Solid state synthesis, luminescent properties and energy transfer from Eu2+ to Mn2+ in red phosphor BaMg2Si2O7:Eu2+,Mn2+

Abstract

A series of red phosphors Ba1-yMg2-xSi2O7: xMn2+,yEu2+ have been synthesized by solid-state reaction at 1200 °C for 4 h under H2 atmosphere. The crystal structure and photoluminescence properties have been measured and analyzed. Under excitation of 342 nm, Eu2+ doped Ba1-yMg2Si2O7 (y = 0.05–0.06) shows violet emission at 400 nm, which is due to the 4f–5d transition of Eu2+, while Mn2+ doped BaMg2-xSi2O7 (x = 0.02–0.40) shows weak reddish emission with a broad band centered at around 640 nm, which is caused by the 4T1(4G) -6A1(6S) transitions of Mn2+. When Eu2+ and Mn2+ were co-doped, excellent red emission is shown under the n-UV excitation. Eu2+ and Mn2+ co-doped BaMg2Si2O7 phosphor shows two intense emission bands with the peak at 400 nm and 660 nm, respectively. The broad emission band for Eu2+ overlaps with the excitation peaks of Mn2+ in the range of 400–450 nm, which shows that the emission of Mn2+ is dominantly ascribed to the persistent energy transfer from Eu2+. By changing the ratio of Eu2+/Mn2+, the emission color can be tuned from violet to red. When the doping content is fixed at 0.16 for Mn2+ and 0.32 for Eu2+, the CIE of the phosphor is (0.495,0.315). Eu2+ and Mn2+ co-doped BaMg2Si2O7 phosphors may have potential application for near-UV light-emitting diodes.