In recent years, SiN4-based covalent nitride materials, including nitridosilicates, and nitridoaluminosilicates have beenextensively studied as good host lattices for white light-emitting diodes (LEDs). In this study, Eu2+-doped strontiumnitridosilicate (Sr2Si5N8 : Eu2+) red phosphor was successfully synthesized using a direct reaction among strontium carbonate(SrCO3), Eu2O3, and Si3N4. The single-phase Sr2Si5N8 : Eu2+ phosphor was obtained by firing at 1550 oC for 2 hrs under a0.4 MPa (N2+ 4% H2) atmosphere. The synthesized Sr2Si5N8:Eu2+ phosphor presented a broadband excitation spectrumbetween 300 and 500 nm, which matches well the blue emission (400-460 nm) of current InGaN LEDs. The temperaturedependence of the photoluminescence properties of the prepared Sr2Si5N8 : Eu2+ phosphor was investigated from 25 to 200 oC,and the activation energy (ΔE) for thermal quenching was determined by Arrhenius tting. This phosphor, with an encapsulant,was incorporated into an InGaN LED (λmax = 440 nm), and the CIE chromatic coordinates and color rendering index of thewhite light were measured from 20 to 100 mA.

Keywords: White LEDs, Sr2Si5N8 : Eu2+, Phosphor, Photoluminescence, Thermal quenching