Comparative analysis on microhardness and third order nonlinear optical traits of pure and Nd3+ doped zinc tris-thiourea sulphate (ZTS) crystal

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 (DCCT) 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.