Temperature-Dependent Luminescence Characteristic of SrSi2O2N2：Eu2＋ Phosphor and Its Thermal Quenching Behavior

The yellow SrSi2O2N2：Eu2＋ phosphor has been synthesized by using a simple solid-state reaction method with Sr2SiO4：Eu2＋ as the precursor. It shows a broad excitation band extending from 250 to 520 nm and an asymmetric emission band with a main peak at about 550 nm. The emission intensity of the SrSi202N2：Eu2＋ is about 1.2 times higher than the commercial yellow phosphor YAG：Ce3＋ （P46-Y3）. The temperature- dependent luminescence characteristic of SrSi202N2：Eu2＋ has been investigated in this paper. With increasing temperature, the emission band of SrSi202N2：Eu2＋ shows anomalous blue-shift along with decreasing emission intensity and the broadening full width at half maximum （FWHM）. Particularly, compared with YAG：Ce3＋ （P46-Y3）, the yellow SrSi202N2：Eu2＋ phosphors exhibit higher thermal stability due to their weaker electron-phonon coupling strength （1.1）, lower stokes shift （0.0576 eV） and larger activation energy （0.288 eV）. All these results indicate that SrSi202N2：Eu2＋ yellow phosphors have potential application for white light-emitting diodes （LEDs）, What＇s more, an energy level scheme is constructed to explain the anomalous blue-shift phenomenon.