Color converter based on transparent Ce:YAG ceramic by different package structure for high-power white LED. Issue 17 (1st December 2019)

• Record Type: Journal Article
• Authors: Qian, Xinglu; Li, Yang; Shi, Mingming; Yang, Bobo; Zheng, Fei; Liu, Zizhuan; Zou, Jun
• Is Part Of: Ceramics international. Volume 45:Issue 17(2019)Part A
• Page Start: 21520
• Page End: 21527
• Publication Date: 2019-12-01
• Subjects: Ce -- YAG ceramic -- Phosphor film -- High-power white LED; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2019.07.145
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Ce: GdYAG ceramics and CaAlSiN3 : Eu 2+ phosphor were fabricated by solid-state reaction. CaAlSiN3 : Eu 2+ phosphor films with different content were manufactured on Ce: YAG ceramic by the spin-coating method. The Ce: YAG ceramics doping with different Gd 3+ content is labeled as Gd-doping structure. The red phosphor film placing Ce: YAG ceramic close to the chips is labeled as R–Y structure, similarly, the red phosphor film adjacent to the chips is named as Y-R structure. The main emission peak has redshift with Gd content increase. The PL spectra have a shift to the red region with the increasing of the red phosphor content in the R–Y structure and Y-R structure. As-prepared samples were further fixed on the substrate to manufacture the ceramic covered film (CCF)-based LEDs and ceramic-based LEDs. The color temperature can be regulated through the three structure. The luminous efficacy in the R–Y structure, Y-R structure, and Gd-doping structure is 89.16 lm/w, 86.8 lm/w, and 62.9 lm/w at about 3500K, respectively. The CRI in the R–Y structure, Y-R structure, and Gd-doping structure is 64.6, 68.8, and 62.2 at about 3500K, respectively. The temperature in the R–Y structure, Y-R structure, and Gd-doping structure 83.3 °C, 81 °C, and 124.7 °C at about 3500K, respectively. The heat dissipation capability of R–Y structure and Y-R structure are superior to that of the Gd-doping structure. The result shows that the R–Y structure has the best luminous efficacy at a similar CCT which improved 41.7% comparing to the Gd-doping structure. The Y-R structure has the best CRI (improve 10.6% comparing to the Gd-doping structure) and heat dissipation capability (decreased 35.1% comparing to the Gd-doping structure) at a similar CCT. The way of Ce: YAG ceramic coated CaAlSiN3 : Eu 2+ phosphor will be a promising candidate to achieve warm white for high power LEDs.