Distinctive spatially separated structure of dichromatic phosphor-in-glass film for high-quality laser lighting

Dichromatic phosphor-in-glass films (PiFs) are recognized as ideal color converters for high-quality laser lighting, but photon reabsorption among multiple phosphor degrades the luminescence performance. Therefore, there is urgent to design a suitable PiF structure to alleviate this problem. Herein, the green-emitting phosphor YAGG:Ce and the orange-yellow-emitting phosphor GdYAG:Ce are mixed with silicate glass powder respectively, and print on the sapphire plate with high thermal conductivity (TC) to prepare spatially separated structure PiF (SS-YG PiF). Under the excitation of blue LD with power of 6.15 W, the luminous flux (LF) of SS-YG PiF reaches 1020.4 lm, and the corresponding luminous efficiency (LE) reaches 165.92 lm/W and CRI∼80. Notably, the perfect white light color coordinates (0.3354, 0.3253) are obtained at 6.15 W. In addition, SS-YG PiF has a lower surface temperature and a higher TC (9.89 W m −1 K −1 ), reflecting the excellent luminescence performance and thermal properties of SS-YG PiF.