Tailoring of deep-red luminescence in Ca₂SiO₄:Eu ²⁺

We report a new dicalcium silicate phosphor, Ca_2-xEu _xSiO₄, which emits red light in response to blue-light excitation. When excited at 450 nm, deep-red emission at 650 nm was clearly observed in Ca_1.2Eu_0.8SiO₄, the external and internal quantum efficiencies of which were 44 % and 50 %, respectively. The red emission from Ca_2-xEu_xSiO₄ was strongly related to the peculiar coordination environments of Eu²⁺ in two types of Ca sites. The red-emitting Ca₂SiO₄:Eu ²⁺ phosphors are promising materials for next-generation, white-light-emitting diode applications. A dicalcium silicate phosphor, Ca _2-xEu_xSiO₄, emits red light in response to blue-light excitation. When excited at 450 nm, deep-red emission at 650 nm was clearly observed in Ca_1.2Eu_0.8SiO₄. The picture shows a photograph of the corresponding Ca_1.20Eu _0.80SiO₄ phosphor upon excitation with blue LEDs. The external and internal quantum efficiencies were 44 % and 50 %, respectively.