Optical and Thermal Performances of PiG-Based WLEDs With Different Packaging Structures.

Phosphor-in-glass (PiG)-based white light-emitting diodes (WLEDs) are regarded as promising solid-state lighting sources because of their high efficiency, excellent thermal stability, and facile packaging process. In this letter, we investigated the optical and thermal performances of PiG-based WLEDs with different packaging structures. The PiG converter was prepared by printing and sintering a phosphor glass film on a sapphire plate. Three types of PiG-based WLEDs were fabricated, PiG on chip (PiG-1), PiG with air gap (PiG-2), and PiG with silicone encapsulation (PiG-3). The experimental results show that the PiG-1 sample achieves a highest luminous efficacy (LE) of 110.5 lm/W, a correlated color temperature (CCT) of 6080 K, and a color rendering index (CRI) of 70.5. In addition, the PiG-2 sample displays a lowest working temperature under various currents. [ABSTRACT FROM AUTHOR]