A novel red-emitting Eu3+-doped Na2MgSiO4 phosphor with high intensity of 5D0 → 7F4 transition

Novel red-emitting Na2MgSiO4: Eu3+ phosphors with different Eu3+ contents were synthesized by sol-gel method. The crystal structure was confirmed by X-ray powder diffraction. The luminescence properties and decay curves were investigated. The optical Eu3+ doping concentration of Na2MgSiO4: Eu3+ is about 5 mol%. The excitation spectrum exhibits a broad band of 250-500 nm. The abnormal dominant emission peak of Na2MgSiO4: Eu3+ phosphors excited effectively by 393.5 nm (near-UV) is located at 702 nm due to the 5D0 → 7F4 transition that caused by the highly polarizable chemical circumstance. The CIE chromaticity coordinate and the photoluminescence quantum yield of the Na2MgSiO4: 0.05Eu3+ phosphor are (0.644, 0.355) and 65.81%, respectively. The mechanism of concentration quenching can be attributed to the dipole-dipole interaction between Eu3+ ions and the thermal quenching might be ascribed to the competition between energy transfer and crossover process.