High color rendering index of warm WLED based on LuAG: Ce 3+ PiG coated CaAlSiN 3 : Eu 2+ phosphor film for residential lighting applications

The high color rendering index of warm white light-emitting diode (WLED) was fabricated using LuAG: Ce 3+ PiG coated CaAlSiN 3 : Eu 2+ phosphor film as converted materials. The LuAG: Ce 3+ PiG and CaAlSiN 3 : Eu 2+ phosphor film was prepared by low-temperature co-sintering and spin coating route, respectively. In this work, the thermal stability of LuAG: Ce 3+ PiG through the thermal shock test was discussed. After that, the optical properties of Lu 2.94−x Y x Al 5 O 12 : 0.06Ce 3+ (x = 0, 0.2, 0.4, 0.6, 0.8) PiG coated CaAlSiN 3 : Eu 2+ phosphor film converted WLEDs were investigated. When x value is 0.4, it exhibits a color rendering index of 94, correlated color temperature of 3087 K and luminous efficiency of 62 lm/W under 20 mA current driving. The package method has excellent developing potential for residential lighting applications.