A light emitting device includes a light source that emits first light in
response to an electrical signal, and a fluorescent layer positioned over
the light source. The fluorescent layer includes a first fluorescent
material which radiates second light and a second fluorescent material
which radiates third light. In one embodiment, the second fluorescent
material contains europium activated calcium sulfide. In another
embodiment, the second fluorescent material contains europium activated
nitrido-silicate. In some embodiments, the device includes a light
propagation medium which transmits the first, second, and third light as
composite output.