A high quantum efficiency CaAlSiN3:Eu2+ phosphor-in-glass with excellent optical performance for white light-emitting diodes and blue laser diodes

By Yujie Zhang, Zelong Zhang, Xiaodong Liu, Guangzhan Shao, L. Shen, Jianming Liu, W. Xiang, Xiaojuan Liang. 2020

153 citations recorded by the source corpus.

Abstract CaAlSiN3:0.2%Eu2+ (CASN:Eu2+), an excellent red phosphor, plays a leading part in wide color gamut and high color rendition white light-emitting diodes (wLEDs). However, this phosphor or silicone resin mixture possesses a fatal defect of an intrinsic low thermal performance, which makes it hardly useful in high-power laser lighting and displays. Here, to improve the thermal performance of the CASN:Eu2+ phosphor, a series of red-emitting phosphor-in-glass materials (R-PiGs) with different CASN:Eu2+ concentrations (5–50 wt%) and sintering temperatures (750–850 °C) were successfully synthesized by dispersing the CASN:Eu2+ phosphor into a B2O3-Na2O-SiO2-CaO glass matrix. Surprisingly, the prepared R-PiGs showed a high external quantum efficiency (EQE) of 53%, and still maintained 82% efficiency compared with the CASN:Eu2+ phosphor (65%). The R-PiGs are superior to red ceramics for low cost and rapid batch preparation. Considering the densification of the R-PiGs, a systematic study was conducted on 10 wt% R-PiG sample. A facile chromaticity tuning for the configured wLEDs was obtained within the color range change from cool white to warm white when using the R-PiGs with different CASN:Eu2+ concentrations. Besides, we have successfully assembled a warm wLED with high luminous efficacy (90.3 lm/W) and color rendering (Ra = 94.2 and CCT = 5053 K). When irradiated by a blue laser, an optimized R-PiG can show enhanced luminous flux (49.27 lm) at a high laser incident power of 1.90 W/mm2. Therefore, with their excellent performances, R-PiGs are highly promising for use as red color converters for potential applications in tunable wLEDs and high-power laser lighting.

Subfields: Materials Chemistry, Renewable Energy, Sustainability and the Environment

View Paper: https://www.semanticscholar.org/paper/6398a64c586f94e8387cbe85f993f0de51657042