White light illumination system with improved color output

摘要

There is provided a white light illumination system including a blue LED and a luminescent material. The system color output is improved when a line connecting the LED color coordinates and the luminescent material color coordinates approximates the Black Body Locus on the CIE chromatically diagram. The LED may have a peak emission wavelength between 470 and 500 nm. The luminescent material may be (Y1-x-z Gdx Cez )3 Al5 O12, where 0.7>x>0.4 and 0.1>z>0.