Abstract: New phosphors which may be activated to luminesce in the red to green portion of the spectrum have an alpha crystal structure isostructural with Ba.sub.2 MnS.sub.3 and the compositionBa.sub.2 Zn.sub.1.sub.-y Cd.sub.y S.sub.3 : A.sub.w.sup.. zZnSwherein A is an activator element selected from the group consisting of manganese, europium, cerium, lead and terbium, y is a numerical value in the range from 0 to 1, z is a numerical value in the range from 0 to 20, and w is a numerical value in the range from 0.00001 to 0.1. Methods of making these phosphors are described.