Efficient solid-state route for the preparation of spherical YAG:Ce phosphor particles

Spherical, micrometer-sized, and polycrystalline Y 3Al 5O 12:Ce +3 (YAG:Ce) powders having good luminescence properties were synthesized via a solid-state processing route from the corresponding submicrometer-sized oxides and 5 wt% BaF 2 flux. It was shown that the nucleation of the spherical YAG particles occurs via the dissolution–precipitation mechanism, whereas the grain growth process is controlled via the liquid-phase diffusion route. [Display omitted] ▶ Solid-state technique was adopted to produce spherical shape YAG:Ce phosphor particles at 1300–1500 °C in CO reducing atmosphere. ▶ The mechanism of nucleation and grain growth of YAG:Ce particles were offered based on XRD, SEM and TEM-EDS analysis data. It was shown that spherical shape particles were formed by high-temperature dissolution–precipitation process. ▶ The YAG:Ce phosphor particles prepared using the proposed technique exhibit a high crystallinity, and PL emission intensity 10–15% higher than that of commercial phosphor powder. The formation of Y 3Al 5O 12:Ce 3+ (YAG:Ce) powders from the corresponding submicrometer-sized oxides and 5 wt% BaF 2 flux is studied at different heating temperatures. The reaction powders are characterized using XRD, SEM, and TEM-EDS. X-ray analysis reveals the sequential formation of the Y 4Al 2O 9 (YAM), YAlO 3 (YAP), and Y 3Al 5O 12 (YAG) phases in the temperature range of 1000–1300 °C. It is shown that the nucleation process occurs via the dissolution–precipitation mechanism, whereas the grain growth process is controlled via the liquid-phase diffusion route. YAG:Ce phosphor particles prepared using a proposed technique exhibit a spherical shape, high crystallinity, and an emission intensity that is approximately 10–15% greater than that of commercial phosphor powder.