High-Performance Phosphor-in-Glass Film on Thermoelectric Generator for Non-Radiative Energy Recycling in Laser Lighting

Huge heat energy is ultimately generated in the color converter as a result of the nonradiative recombination of high-power laser excitation. Inspired by the thermoelectric conversion, a high-performance phosphor-in-glass film (PIGF) coated on a thermoelectric generator (TEG) for nonradiative energy recycling in high-brightness laser lighting is proposed. The heat-resistance PIGF with high luminescence is tightly coated on the hot-side ceramic of TEG, while yielding a bright white light and promoting the heat conduction between PIGF and TEG. At the PIGF thickness of 60 mu m, the PIGF-TEG enables a natural white light with a luminous flux of 464 lm, a luminous efficacy of 194 lm W-1, a correlated color temperature (CCT) of 6552 K, and an appropriate chromaticity coordinate of (0.3117, 0.3302) under a laser power of 2.39 W. Aside from the high-brightness output white light with a luminous flux of 1045 lm, the laser-driven PIGF-TEG produces the output voltage and current of 0.46 V and 174 mA under a laser power of 5.61 W, respectively. Therefore, the proposed PIGF-TEG provides a potential strategy for heat energy recycling in high-power phosphor-converted lighting.