Development of waste glass frits-based phosphor in glass system for solid-state lighting with high thermal stability

Laser-based solid-state lighting is the future of the high-brightness lighting and long-distance automobile illumination industry. It has started replacing light-emitting diode (LED)-based lighting equipment with high thermal stabilities and transparencies, i.e., phosphor in glass (PiG). PiGs have received special attention because of their simple fabrication process and easy colour tuning. The study of glass is usually conducted in the field of phosphor fabrication, with very limited studies on its recycling. We demonstrated the utilization of rejected glass from other sources due to scratches, cracks and defects by some other means by recycling with the development of PiGs. The waste glass slides were crushed into fine powders, and the pulverized samples were sieved to an average particle size of 30 μm. Fine glass frits were mixed with Ce-doped Y₃Al₅O₁₂ and sintered at 730°C for 30 min to refabricate glass as a PiG to overcome the recycling route for waste glass. A prototype design of laser-driven PiGs (LD-PiGs) has been developed for white light generation. Different concentrations of YAG:Ce (20–50%) in fine glass frits had colour rendering indices (CRIs) >60. The 25 wt.% YAG:Ce-developed PiG pellet showed better results than the other compositions in terms of photoluminescence emission intensity, CRI 69, colour-correlated temperature 5566 K and colour coordinates (0.331, 0.3328). PiG pellets are much better than YAG:Ce and UV-adhesive matrix screens printed on glass substrates used as white light sources. LD-PiGs exhibit superior thermal robustness.