Photoluminescence and thermal stability of yellow-emitting Na2Ba2Si2O7:Sm3+ phosphor for light-emitting diodes

A series of yellow-emitting Na2(Ba2−xSmx)Si2O7 phosphors have been prepared via solid-state reaction technique. X-ray diffraction (XRD), photoluminescence (PL) spectra, temperature-dependent luminescence property, concentration quenching mechanism and luminescence lifetime are applied to characterize the obtained samples. Under 402 nm near ultraviolent excitation, the samples emit yellow light and the color purity is close to 100%. The critical quenching concentration of Sm3+ in the Na2Ba2Si2O7 host is about 3.6 mol% and corresponding quenching behavior is ascribed to be electric dipole–dipole interaction. Furthermore, the phosphor has good thermal stability property, superior to the commercial yellow Y3Al5O12:Ce3+ phosphor and the activation energy for thermal quenching is calculated as 0.18 eV.