a green phosphor having the formula (Sr,A1)x(Si,A2)(O,A3)2+x:Eu2+, where A1 is at least one of a divalent alkaline earth or transition metal cation selected from the group consisting of Mg, Ca, Ba, and Zn and where the stoichiometric amount of A1 varies 0.3 to 0.8, both inclusive; A2 is P and A3 is a halogen selected from the group consisting of F and Cl, where the amounts of A2 and A3 each range