The present invention relates to a tri-color lamp for generating white
light. In particular, the invention relates to a phosphor mixture
comprising two phosphors having host sulfide materials that can absorb
radiation emitted by a light emitting diode, particularly a blue LED. This
arrangement provides a mixing of three light sources--light emitted from
the two phosphors and unabsorbed light emitted from the LED. The phosphors
can contain the same dopant, such as a rare earth ion, to allow matching
of the phosphors in relation to the LED emitted radiation. Power fractions
of each of the light sources can be varied to achieve good color
rendering. The present invention also relates to an alternative to a green
LED comprising a single green phosphor that absorbs radiation from a blue
LED. A resulting device provides green light of high absorption efficiency
and high luminous equivalent values.