Phosphor-in-fluorescent-glasses for high color rendering white light emitting diodes

Fluorescent glass frits were prepared and used to synthesize phosphor-in-fluorescent glass composites (PiFGs) to realize stable white light emitting diodes with high color-rendering properties. Commercial red, green, and blue phosphors were co-sintered and red phosphors were partially replaced by Eu3+ in glass frits. Phosphor-in-glass composites were placed on UV-light emitting diodes (UV-LEDs) to generate white light. Pure white light with a luminous efficacy=58.4lm/W, general color rendering index R-a=87 and special color rendering index for strong red R-9=73 was realized with glass frits containing 7mol% Eu2O3 and RGB ratio of 35:20:15. Luminous efficacy, R-a and R-9 increased as red phosphors were replaced by red-fluorescent glass frits.