Emitting area limitation via scattering control in phosphor film realizing high-luminance laser lighting. Issue 2 (February 2022)

• Record Type: Journal Article
• Authors: Xu, Jian; Wang, Lanjie; Gu, Wen; Jiang, Zhi; Chen, Xinrong; Hu, Baofu; Du, Baoli; Ji, Haipeng; Dam-Hansen, Carsten; Jensen, Ole B.
• Is Part Of: Journal of the European Ceramic Society. Volume 42:Issue 2(2022)
• Page Start: 608
• Page End: 615
• Publication Date: 2022-02
• Subjects: Laser lighting -- Luminous exitance -- Composite film -- Spot limitation -- YAG:Ce; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2021.10.035
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: One major benefit of laser lighting is the possibility to achieve very high luminance. In phosphor-converted laser lighting systems, a blue (pump) laser can be focused into a very small spot. However, after excitation of the phosphor, the white-light-emitting area usually increases considerably, which reduces the luminance parameter substantially. Herein, we design and investigate a highly scattering YAG:Ce/glass composite film with a porous microstructure. Both the glass/phosphor interfaces and the introduced pores act as scattering centers, which can confine the emission area effectively. The relationship between the spot size and the microstructure (porosity, phosphor-particle size, thickness) is elucidated. Under excitation with blue laser, the composite film shows a uniform white-light emission with high luminous efficacy (230 lm/W) and high saturation threshold (> 40 W/mm 2 ), thus achieving a high luminous exitance of ∼1239 lm/mm 2 . With above excellent properties, the designed composite films show great potential for use in high-luminance laser lighting.