Improving efficiency and light quality of white LEDs by adding ZrO2 nano-particle and red phosphor in encapsulant

Efficiency and light quality of white light-emitting diodes (LEDs) were improved by adding ZrO
₂
nano-particle and red phosphor in encapsulant. ZrO
₂
nanoparticles can enhance the light scattering ability of encapsulant on LED chip. Doping ZrO
₂
nanoparticles with YAG phosphor into encapsulant package (LED II) luminous flux increase of 7.7 % compared conventional doping YAG phosphor package (LED I). Conformal YAG phosphor on LED chip and doping ZrO
₂
nanoparticles into encapsulant package of white LED (LED III) the luminous flux increase of 19.8 % compared LED II. Doping red phosphor into encapsulant of LED II produced LED IV, CRI can improved from 47 to 90 and R9 from 0 to 90.