Enhancement of luminescence properties of SrAl2Si2O8: Eu3+ red phosphor

Abstract

Aluminosilicate phosphors have been widely used in the fields of fluorescence and laser technology due to its excellent optical properties. However, red phosphors have low luminescence efficiency, and poor physicochemical stability, which cannot achieve efficient white light emission. Therefore, improving the luminescence performance of aluminosilicate red phosphors is a research hotspot in white LED. In this work, SrAl2Si2O8: Eu3+ red phosphor was synthesized by high temperature solid-phase method. By introducing charge compensator and flux, the luminescence intensity of the phosphor is increased. The best charge compensator is determined as Li+ with the same Eu3+ doping content. The best flux is H3BO3, and the optimal doping concentration of flux is 3 wt%. For SrAl2Si2O8: Eu3+, Li+, H3BO3 red phosphor, the CIE coordinates are (0.619, 0.380) and CCT is 3417 K, which is very close to the standard red light. Through LED packaging mixing phosphor with YAG: Ce3+, the method can significantly improve the color rendering index of WLED, up to 84.7. When the temperature reaches 150 °C, the luminescence intensity decreases to 88.02% of the initial value, which indicates that the SrAl2Si2O8 phosphor is an excellent stable red luminescent material.