A Double-Layer White Light Converter with High-Efficiency Heat Transfer Structure for High-Power NUV LEDs/LDs

As a next-generation lighting technology, high-power light-emitting diodes (LEDs) and lasing diodes (LDs) lighting have attracted great attention to high-brightness applications. However, producing an efficient illumination-grade color converter with a conspicuous color rendering index (CRI) and a suitable correlated color temperature (CCT) remains an outstanding challenge in the field of high-power LEDs/LDs lighting. In this work, a double-layer white light converter with high efficiency heat transfer structure was designed and prepared by precisely coating a blue/green emitting phosphor-in-silicone (PIS) film on red emitting transparent ceramic substrate. The well-designed double-layer converter exhibits excellent optical properties that the optical–optical conversion efficiency can achieve 156 lm/W with conspicuous CRI (92.6), CIE chromaticity coordinates (0.332, 0.335), and suitable CCT (5511K). Furthermore, the heat transfer efficiency of the double-layer converter was analyzed and simulated by using infrared thermal imaging and steady-state thermal simulation, which reduce the temperature more efficiently than single-layer converter under high-power NUV LEDs/LDs excitation. These comprehensive performances show that the double-layer converters are promising as NUV LEDs/LDs-driven phosphors in high-power solid-state lighting devices.