Improving color uniformity and color rending index of remote-phosphor packaging white LEDs by co-doping SiO₂ and Sr₂Si₅N₈:Eu²⁺ particles

Based on some advantageous properties, such as fast response time, environment friendliness, small size, long lifetime, and high efficiency, white LEDs are increasingly used in common illumination applications. In this research, by co-doping of redemitting Sr₂Si₅N₈:Eu²⁺ phosphor and adding SiO₂ particles to yellow-emitting YAG:Ce phosphor compounds, a new approach for improving color uniformity and color rending index of remote-phosphor structure white LEDs is proposed and demonstrated. The obtained results clearly indicate that the color rendering index (CRI) and color uniformity (ΔCCT) significantly depend on Sr₂Si₅N₈:Eu²⁺ concentration. The results provide a potential practical solution for manufacturing remote-phosphor white LEDs (RP-WLEDs) in the near future.