Synthesis and luminescent characteristics of Ca2−xSrxSiO4:Eu2+ as a potential green-emitting phosphor for near UV-white LED applications

The photoluminescence properties of enhanced green-emitting Ca2−xSrxSiO4:Eu2+ were optimized for applications to near ultraviolet light emitting diodes (LEDs). The optimal firing conditions for Ca2−xSrxSiO4:Eu2+ prepared by solid-state reaction synthesis were found to be 1300 °C for 6 h. Ca2−xSrxSiO4:Eu2+ showed strong green emission peak at approximately 520 nm under excitation by near UV light of 390 nm. The effects of Sr2+ substitution into the Ca2+ sites on the emission band shift were investigated. The enhanced emission intensity and blue shift in the emission band of Ca2−xSrxSiO4:Eu2+ was explained by competition between crystal field and nephelauxetic effect. These characteristics make Ca2−xSrxSiO4:Eu2+ a good candidate for green-emitting phosphors in the production of white light in phosphor conversion white LEDs.