High color rendering and high-luminance laser lighting using all inorganic nitride phosphor films

• Published in: RSC advances Vol. 13; no. 36; pp. 25561 - 2557
• Main Authors: Jiang, Zhi, Yuan, Shaoda, Xu, Jian, Du, Baoli, Xu, Peng, Zhang, Le, Kang, Jian, Zhao, Yujie, Dam-Hansen, Carsten, Jensen, Ole Bjarlin
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 25.08.2023; The Royal Society of Chemistry
• Subjects: Cerium; Chemistry; Composite materials; Laser applications; Lasers; Light emission; Light sources; Lighting; Luminance; Luminous efficacy; Optical properties; Phosphors; Rendering; Thermodynamic properties; White light
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d3ra04062c

Despite the huge advances that have been made in the development of ultra-high luminance laser lighting, achieving high color rendering properties in such systems at the same time remains a challenge. Recent studies show that in most cases, the luminous efficacy (LE) of laser lighting is compromised to improve the color rendering index (CRI). In this study, a possible solution to this problem has been proposed by preparing phosphor-in-glass (PiG) films comprised of the yellow-emitting phosphor (LSN:Ce 3+ ) and the red-emitting phosphor (CASN:Eu 2+ ). The composite material synthesized in this study exhibited outstanding optical and thermal properties. A uniform white light with a high CRI of 80.0 and a high LE of 185.9 lm W −1 was achieved by optimizing the yellow/red ratio and the emission peak position of the blue laser. Furthermore, it was found that this design enabled the phosphor to restrict the light emission area effectively, thus attaining a high luminous exitance of 1302 lm mm −2 . With their superior optical performance, the PiG films can be regarded as promising color converter candidates for future high-quality laser-based white light sources. All-inorganic PiG-Fs with dual nitride phosphors are fabricated by screen printing and a good balance between the color rending and the efficiency is achieved. High luminance is achieved via effective light confinement and good heat dissipation.