A single-component white-emitting electroluminescent phosphor and its method of making are described. The single-component phosphor exhibits a white emission having an x color coordinate of 0.23 to 0.41 and a y color coordinate of 0.25 to 0.42. The phosphor is comprised of zinc sulfide activated with copper, manganese, chlorine, and, optionally, one or more metals selected from gold and antimony.