Enhancement of optical performance and thermal stability of LuAG: Ce phosphor-in-glass via a new TS plus SPS method for laser lighting

Phosphor -in -glass (PiG) has attracted widespread attention as a phosphor converter for laser lighting, and the optimization of its optical properties has always been a focus of research. In this study, we successfully obtained a series of Lu 3 Al 5 O 12 : Ce 3+ (LuAG: Ce) phosphor -in -glass (LuAG-PiG) samples made from LuAG: Ce phosphor and a 70.4SiO 2 -8.5Na 2 O-4.2Al 2 O 3 -2.2B 2 O 3 -1.4TiO 2 -2.1ZnO-1.4CaO-4.9Li 2 O-4.9K 2 O (mol%) glass matrix via a new method of additional tablet sintering prior to spark plasma sintering (TS + SPS). Compared to individual SPS, the new method successfully resolved the carbon contamination problem inherent to SPS. Meanwhile, the new method significantly enhanced the optical and thermal properties when compared with TS. Under the 450-nm blue laser excitation with 5.6 W mm -2 , the optimal LuAG-PiG realized a maximum luminous flux (LF) of 746 lm (40 % higher than that of the sample prepared by TS). Additionally, the initial luminous efficiency (LE) of the most optimal LuAG-PiG was promoted to 305.2 lm/W (23 % higher than that of the sample prepared by TS). Furthermore, the most optimal LuAG-PiG exhibited low thermal quenching and high thermal stability (it maintained 87.3 % at 473 K). These results demonstrate that this new method is promising for the future preparation of efficient phosphor -in -glass mediums for laser lighting.