Optothermal Performances Investigation of Phosphor-Converted White LDs With Alumina Substrate-Based PiGF Converters

Phosphor-in-glass film(PiGF)-based phosphor-converted white laser diode (pc-WLD) is regarded as a potential high-brightness white lighting source. For reflective PiGF converters, the optothermal performances are particularly related to heat dissipation efficiency, mainly depend on the heat-conducting substrate and extra heat dissipation method. In this article, we prepared PiGF-Al2O3 substrate (PiGF-AS)converters by coating and sintering LSN:Ce phosphor glass film directly on Al(2)O(3 )substrates to slash thermal conduction resistance. The other factors that significantly impact heat dissipation efficiency-substrate size (area and thickness) and the presence or absence of heat sink-are extensively evaluated in the PiGF-AS-based pc-WLD. It is delightful to find that both the optical performance and reliability of PiGF-AS could be improved by expanding the substrate area, increasing substrate thickness, and combining the heat sink. The PiGF-AS achieves a maximum luminous flux (LF) of 1564 lm under a laser power density of 12.36 W/mm(2). The PiGF-AS-based pc-WLD with 5x5x0.5 mm(3)Al(2)O(3) substrate realizes cool white lighting with a correlated color temperature (CCT) of 4918 K and a chromaticity coordinate of (0.3440, 0.3592). Furthermore, the working temperature of PiGF-AS is reduced by the heatsink from 218(degrees)C to 58.3(degrees)C (similar to 73.1%) under a 3.18-W/mm(2 )laser. The results show that the prepared PiGF-AS-based pc-WLD shows excellent optothermal performances and great potential in white laser lighting. Meanwhile, this work provides a reference for the high heat-dissipation packaging design of PiGF-based pc-WLD