Properties of red-emitting phosphors Sr2MgSi2O7:Eu3+ prepared by gel-combustion method assisted by microwave

Novel red-emitting phosphors Sr2MgSi2O7:Eu3+ were prepared by gel-combustion method assisted by microwave. The phase structure and luminescent properties of as-synthesized phosphors were investigated by XRD and fluorescence spectrophotometer, respectively. The results showed that the as-synthesized sample was Sr2MgSi2O7 with tetragonal crystal structure. The excitation spectrum of Sr2MgSi2O7:Eu3+ was composed of two major parts: one was the broad band between 200 and 350 nm, which belonged to the charge transfer of Eu3+−O2−; the other consisted of a series of sharp lines between 350 and 450 nm, ascribed to the f-f transition of Eu3+. The emission spectrum consisted of two emission peaks at 593 and 616 nm, which was attributed to 5D0→7F1 and 5D0→7F2 of Eu3+, respectively. The concentration of Eu3+ (x) had great effect on the emission intensity of Sr2−xMgSi2O7:Eu3+x. When x varied in the range of 0.04–0.18, the intensity of emission peaks at 593 and 616 nm increased gradually with the concentration of Eu3+ increasing. It was interesting that no concentration quenching occurred. Moreover, the luminescent intensity could be greatly enhanced with incorporation of charge compensator Li+ ions.