Red phosphors for use in high cri fluorescent lamps

摘要

Novel red emitting phosphors for use in fluorescent lamps (10) resulting in superior color rendering index values compared to conventional red phosphors. Also disclosed is a fluorescent lamp (10) including a phosphor layer (16) comprising blends of one or more of a blue phosphor, a blue-green phosphor, a green phosphor and a red a phosphor selected from the group consisting of SrY2O4:Eu<3+>, (Y,Gd)Al3B4O12:Eu<3+>, and Ä(Y1-x-y-mLay)GdxÜBO3:Eum wherein y<0.50 and m=0.001-0.3. The phosphor layer (16) can optionally include an additional deep red phosphor and a yellow emitting phosphor. The resulting lamp (10) will exhibit a white light having a color rendering index of 90 or higher with a correlated color temperature of from 2500 to 10000 Kelvin. The use of the disclosed red phosphors in phosphor blends of lamps results in high CRI light sources with increased stability and acceptable lumen maintenance over the course of the lamp (10) life.