US Patent 10468564 Packaged white light emitting device comprising photoluminescence layered structure

A white light emitting package (20) comprises: a solid-state excitation source (LED 30) for generating excitation light with a dominant wavelength in a range 440 nm to 470 nm; and a layered photoluminescence structure. The layered photoluminescence structure comprises a first photoluminescence layer (32) comprising from 75 wt % to 100 wt % of a manganese-activated fluoride photoluminescence material of the total photoluminescence material content of the first photoluminescence layer, and a second photoluminescence layer (34) comprising photoluminescence material for generating light with a peak emission wavelength in a range from 500 nm to 650 nm. The second photoluminescence layer is disposed on the first photoluminescence layer and the first photoluminescence layer is in closer proximity to the solid-state excitation source than the second photoluminescence layer.