Fabrication of phosphor glass film on aluminum plate by using lead-free tellurite glass for laser-driven white lighting

Laser-driven white lighting is regarded as a next-generation high-power lighting because of the advantages of directional light emission, high brightness, and quasi-point source. In this work, we proposed a phosphor-aluminum composite (PAC) converter for laser-driven white lighting. The PAC was fabricated by sintering a phosphor glass film on an aluminum plate by using a lead-free tellurite glass. By adjusting the tellurite component, the tellurite glass achieves similar expansion coefficient with the aluminum, which can eliminate the crack and delamination of PAC. The yellow (Y) and yellow/red (Y/R) PACs were prepared by adding commercial Y3Al5O12:Ce3+ (YAG:Ce3+) and CaAlSiN3:Eu2+ (CASN:Eu2+) into the tellurite glass. These PACs were used as the reflective configuration of white laser diodes (LDs). As the layer number of phosphor glass film increases, the PAC-based white LDs with different optical performances were realized. Furthermore, the phosphor glass films of PACs display extremely low working temperature (<35 °C) under various laser powers due to the high thermal conductivity of aluminum plate. These results indicate that the prepared PAC is an efficient and stable color converter for high-brightness laser-driven white lighting.