Luminescent properties of green- or red-emitting Eu2+-doped Sr3Al2O6 for LED

►Sr3Al2O6:Eu2+ is synthesized by a solid-state reaction under different atmospheres. ►Phosphor obtained under H2+N2 atmosphere emits green light under NUV excitation. ►Phosphor obtained under CO atmosphere emits red light under blue light excitation. ►Different emission wavelengths are due to Eu2+ in different Sr2+ sites. ►The preferential substitution and the substitution rates of Eu2+ are discussed.