Development of waste glass frits-based Phosphor in Glass light system for high thermal stability

Laser based solid state lighting is the future of high brightness lighting and long-distance automobile illumination industry and it has started replacing the light emitting diode (LED) based lighting equipment with high thermal stabilities and transparencies, i.e., phosphors-in-glass (PiG). The various schemes of packing technology have been implemented to improve the extraction efficiency of LEDs, in these methods, PiGs got special attention because of its simple fabrication process and easy color tunable characteristics [1,2]. With increasing attention on PiGs, the research on glass materials also attracted industry to actively conduct research. The study of glass is usually conducted in the field of phosphor fabrication and a very limited study on their recycling is reported. The main purpose of this work was to utilize rejected glass from other sources due to the scratches, cracks, and defects by some other means by recycling with the development of PiGs. The waste micro glass-slides were crushed into fine powders and filter the pulverized sample through a sieve to get an average particle size of 20μm and after that we mixed the fine glass frits with Ce doped Y3Al5O12, (yellow phosphor) and sintered at glass softening temperature about 700-730˚C for 30 minutes to refabricate glass as a PiG to overcome the broaden of the recycling route for waste glass. The developed prototype design of laser diode PiGs system (LD-PiGs) for white light generation with different concentration of YAG: Ce (2-25%) in fine glass frits shows CRI above 60 and 25% of YAG: Ce developed PiGs pallets show better results in comparison to other compositions with CRI 61, color temperature 4327K and CIE1931 (0.3687, 0.4147), which is much better than YAG: Ce and UV Adhesive matrix printed on glass substrate. The LD-PiGs exhibit superior thermal robustness, but they experience low light extraction and poor light uniformity.