Chromaticity-tunable color converter of CaAlSiN3:Eu2+ red phosphor film layer stacked YAG PiG for warm-WLED

We realized a facile chromaticity tuning for the YAG:Ce3+ phosphor-in-glass (PiG) based WLEDs (white light-emitting diodes) by tape casting CaAlSiN3:Eu2+ red film layer on PiG plate and then encapsulated to a remote-type stacking configuration. Experimental results indicated that the color converting material realized a tunable chromaticity quality and yield high luminous efficiency. Microstructures were investigated to reveal the state of phosphor dispersion, as well as interaction of PiG substrate with red film layer. Besides, the thickness of red films was discussed in detail to illustrate its influence on the luminous properties. The optimized WLED exhibits excellent optical performance with a luminous efficiency of 95.76 lm/W, a correlated color temperature of 3949 K, a color rendering index of 82.2, and a color shift deviation from Planckian locus in D-uv of 0.0043. The color converter with good heat-resistance performance is expected to be a promising indoor high-quality general lighting source.