Cehlorosilicate-based phosphors configured to emit yellow-green light in a wavelength ranging from about 500 nm to about 560 nm in response to an excitation source emitting at about 400 nm to about 480 nm, wherein the light emitted by the phosphor has a decay time ranging from about 1 millisecond (1 ms) to about 10 milliseconds (10 ms). The phosphor comprises a compound of the family Ca8-x-yAxEuyMg1-m-nBmMnn(Si1-sCsO4)4R2, where A is at least one divalent cation including Ca, Sr, Ba; B is Zn or Cd, or a divalent metal ion other than an alkaline earth; C is a cation, including at least one of Ge, Al, B, Gd, Ga, and N, and R is an anion, including F, Cl, Br, I, all respectively either individually, or in combinations.