Enhanced Color Quality of WLEDs by Cone-Shape Multi-Color Phosphor-in-Glass

Herein, luminescence-tunable white light-emitting diodes (WLEDs) with enhanced color quality were fabricated by cone-shape multi-color phosphor-in-glasses (PiGs) with 3D ceramic substrate. The optical performance of WLEDs was studied by adjusting the red film thickness of PiG and the cavity depth of ceramic substrate. As the cavity depth increases from 1 to 1.3 mm, the luminous efficiency (LE) and correlated color temperature (CCT) increase first and then decrease. The LE and CCT decrease with the increase of red film thickness. Besides, the WLEDs packaged by varied cavity depth and red phosphor thickness all achieve a CRI of above 80. The PiG3-WLED gains a CCT deviation of 243 K, which improve 90.4% and 71.2% than that of PiG1-WLED and PiG2-WLED, respectively. The results demonstrate that the proposed WLEDs can achieve high color uniformity and good CRI with tunable luminescence.