Monochromatic Amber Light Emitting Diode with YAG and CaAlSiN3 Phosphor in Glass for Automotive Applications

  • Lee, Jeong Woo (Department of Advanced Materials Engineering, Korea Polytechnic University) ;
  • Cha, Jae Min (Department of Advanced Materials Engineering, Korea Polytechnic University) ;
  • Kim, Jinmo (Micro LED Research Center, Korea Photonics Technology Institute) ;
  • Lee, Hee Chul (Department of Advanced Materials Engineering, Korea Polytechnic University) ;
  • Yoon, Chang-Bun (Department of Advanced Materials Engineering, Korea Polytechnic University)
  • Received : 2018.10.29
  • Accepted : 2018.11.28
  • Published : 2019.01.31


Monochromatic amber phosphor in glasses (PiGs) for automotive LED applications were fabricated with $YAG:Ce^{3+}$, $CaAlSiN_3:Eu^{2+}$ phosphors and Pb-free silicate glass. After synthesis and thickness-thinning process, PiGs were mounted on high-power blue LED to make monochromatic amber LEDs. PiGs were simple mixtures of 566 nm yellow YAG, 615 nm red $CaAlSiN_3:Eu^{2+}$ phosphor and transparent glass frit. The powders were uniaxially pressed and treated again through CIP (cold isostatic pressing) at 200 MPa for 20 min to increase packing density. After conventional thermal treatment at $550^{\circ}C$ for 30 min, PiGs were applied by using GPS (gas pressure sintering) to obtain a fully dense PiG plate. As the phosphor content increased, the density of the sintered body decreased and PiGs containing 30 wt% phosphor had full sintered density. Changes in photoluminescence spectra and color coordination were investigated by varying the ratio of $YAG/CaAlSiN_3$ and the thickness of the plates. Considering the optical spectrum and color coordinates, PiG plates with $240{\mu}m$ thickness showed a color purity of 98% and a wavelength of about 605 nm. Plates exhibit suitable optical characteristics as amber light-converting material for automotive LED applications.


$YAG:Ce^{3+}$;$CaAlSiN_3:Eu^{2+}$;Phosphor in glass (PiG);Glass frit;Amber LED


Supported by : National Research Foundation of Korea (NRF)


  1. N. Narendran and Y. Gu, "Life of LED-based White Light Sources," J. Disp. Technol., 1 167-71 (2005).
  2. G. A. Luoma and R. D. Rowland, "Environmental Degradation of an Epoxy Resin Matrix," J. Appl. Polym. Sci., 32 [7] 5777-90 (1986).
  3. N. Narendran, Y. Gu, J. P. Freyssinier, H. Yu, and L. Deng, "Solid-State Lighting: Failure Analysis of White LEDs," J. Cryst. Growth., 268 [3] 449-56 (2004).
  4. M.-H. Chang, D. Das, P. V. Varde, and M. Pecht, "Light-Emitting Diodes Reliability Review," Microelectron. Reliab., 52 [5] 762-82 (2012).
  5. S. Nishiura, S. Tanabe, K. Fujioka, and Y. Fujimoto, "Properties of Transparent Ce:YAG Ceramic Phosphors for White LED Degradation of an Epoxy Resin Matrix," Opt. Mater., 33 688-91 (2011).
  6. M. Raukas, J. Kelso, Y. Zheng, K. Bergenek, D. Eisert, A. Linkov, and F. Jermann, "Ceramic Phosphor for Light Conversion in LEDs," ECS J. Solid State Sci. Technol., 2 [2] R3168-76 (2013).
  7. S. Fujita, A. Sakamoto, and S. Tanabe, "Luminescence Characteristics of YAG Glass-Ceramic Phosphor for White LED," IEEE J. Sel. Top. Quantum Electron., 14 [5] 1387-91 (2008).
  8. R. Mueller-Mach, G. O. Mueller, M. R. Krames, O. B. Shchekin, P. J. Schmidt, H. Bechtel, C.-H. Chen, and O. Steigelmann, "All-Nitride Monochromatic Amber-Emitting Phosphor-Converted Light-Emitting Diodes," Phys. Status Solidi RRL, 3 [7-8] 215-17 (2009).
  9. S. Fujita, S. Yoshihara, A. Sakamoto, S. Yamamoto, and S. Tanabe, "YAG Glass-Ceramic Phosphor for White LED (I): Background and Development," Proc. SPIE., 5941 186-92 (2005).
  10. S. Tanabe, S. Fujita, S. Yoshihara, A. Sakamoto, and S. Yamamoto, "YAG Glass-Ceramic Phosphor for White LED (II): Luminescence Characteristics," Proc. SPIE., 5941 193-98 (2005).
  11. S. C. Allen and A. J. Steckl, "A Nearly Ideal Phosphor-Converted White Light-Emitting-Diode," Appl. Phys. Lett., 92 [14] 143309 (2008).
  12. Y. K. Lee, J. S. Lee, J. Heo, W. B. Im, and W. J. Chung, "Phosphor in Glasses with Pb-free Silicate Glass Powders as Robust Color-Converting Materials for White LED Applications," Opt. Lett., 37 [15] 3276-78 (2012).
  13. Y. K. Lee, Y. H. Kim, J. Heo, W. B. Im, and W. J. Chung, "Control of Chromaticity by Phosphor in Glasses with Low Temperature Sintered Silicate Glasses for LED Applications," Opt. Lett., 39 [14] 4084-87 (2014).
  14. C.-B. Yoon, S. Kim, S.-W. Choi, C. Yoon, S. H. Ahn, and W. J. Chung, "Highly Improved Reliability of Amber Light Emitting Diode with Ca-${\alpha}$-SiAlON Phosphor in Glass Formed by Gas Pressure Sintering for Automotive Applications," Opt. Lett., 41 [7] 1590-93 (2016).
  15. R.-J. Xie, N. Hirosaki, K. Sakuma, Y. Yamamoto, and M. Mitomo, "$Eu^{2+}$-doped Ca-${\alpha}$-SiAlON: A Yellow Phosphor for White Light-Emitting Diodes," Appl. Phys. Lett., 84 [26] 5404-6 (2004).
  16. S. Yu, Y. Tang, Z. Li, K. Chen, X. Ding, and B. Yu, "Enhanced Optical and Thermal Performance of White Light-Emitting Diodes with Horizontally Layered Quantum Dots Phosphor Nanocomposites," Photonics Res., 6 [2] 90-8 (2018).
  17. S.-W. Jeon, J. H. Noh, K. H. Kim, W. H. Kim, C. Yun, S. B. Song, and J. P. Kim, "Improvement of Phosphor Modeling Based on the Absorption of Stokes Shifted Light by a Phosphor," Opt. Express, 22 [5] A1237-42 (2014).