Browse > Article
http://dx.doi.org/10.3807/KJOP.2013.24.2.064

Analysis of Luminous Characteristics of White LEDs Depending on Yellow Phosphors  

Choi, Hyun-Woo (Department of Physics, Hallym University)
Ko, Jae-Hyeon (Department of Physics, Hallym University)
Publication Information
Korean Journal of Optics and Photonics / v.24, no.2, 2013 , pp. 64-70 More about this Journal
Abstract
In this paper, two white light emitting diodes(LEDs) were manufactured by using two kinds of yellow phosphor, YAG:Ce and $(Sr,Ba)_2SiO_4:Eu$, and their spectroscopic properties were compared and analyzed. We found that the asymmetric double sigmoidal function can be applied to both white LEDs to obtain the center wavelength, the half width, and the skewness parameters. According to this analysis, the half width of the emitting spectrum of silicate phosphor was smaller than that of YAG phosphor, indicating smaller color rendering index. However, the silicate phosphor exhibited better color stability depending on the driving current than the YAG phosphor. The current dependence of the luminous efficacy of both white LEDs was investigated, which showed that efficacy decreased monotonically with current. The efficacy of the silicate-based white LED was lower than that of the YAG-based LED by about 10~12 lm/W.
Keywords
White LED; Yellow phosphor; Luminous characteristics;
Citations & Related Records
Times Cited By KSCI : 7  (Citation Analysis)
연도 인용수 순위
1 J. S. Ryu, M.-Y. Yu, S.-M. Park, S. J. Kim, and J.-H. Ko, "Initial photometric and spectroscopic characteristics of 55-inch CCFL and LED backlights for LCD-TV applications," Journal of the KIIEE 24, 8-13 (2010).   과학기술학회마을   DOI   ScienceOn
2 F. Reifegerste and J. Lienig, "Modelling of the temperature and current dependence of LED spectra," J. Light Vis. Environ. 32, 18-24 (2008).
3 A. Keppens, W. R. Ryckaert, G. Deconinck, and P. Hanselaer, "Modeling high power light-emitting diode spectra and their variation with junction temperature," J. Appl. Phys. 108, 043104 (2010) and references therein.   DOI   ScienceOn
4 S. S. Jeong and J.-H. Ko, "Analysis of the spectral characteristics of white light-emitting diodes under various thermal environments," J. Inf. Disp. 13, 37-42 (2012).   과학기술학회마을   DOI
5 A. Keppens, W. R. Ryckaert, G. Deconinck, and P. Hanselaer, "High power light-emitting diode junction temperature determination from current-voltage characteristics," J. Appl. Phys. 104, 093104 (2008).   DOI   ScienceOn
6 J. H. Youk, D. W. Hong, and S. J. Lee, "Basic design guidelines for LED lamp packages," Korean J. Opt. Photon. (Hankook Kwanghak Hoeji) 22, 141-150 (2011).   과학기술학회마을   DOI   ScienceOn
7 H.-D. Yim, D.-J. Lee, Y. G. Kim, and B.-H. O, "Beam pattern analysis of LED reflector design and simplification of the functional design," Korean J. Opt. Photon. (Hankook Kwanghak Hoeji) 23, 222-226 (2012).   과학기술학회마을   DOI   ScienceOn
8 M. Zachau, D. Becker, D. Berben, T. Fiedler, F. Jermann, and F. Zwaschka, "Phosphors for solid state lighting," Proc. SPIE 6910, 691010 (2008).
9 E. F. Schubert, Light-Emitting Diodes (Cambridge University Press, Cambridge, New York, 2006).
10 I. Kim and K. Chung, "Wide color gamut backlight from three-band white LED," J. Opt. Soc. Korea 11, 67-70 (2007).   과학기술학회마을   DOI   ScienceOn
11 Y. Narukawa, M. Ichikawa, D. Sanga, M. Sano, and T. Mukai, "White light emitting diodes with super-high luminous efficacy," J. Phys. D: Appl. Phys. 43, 354002 (2010).   DOI   ScienceOn
12 Y. Narukawa, I. Niki, K. Izuno, M. Yamada, Y. Murazaki, and T. Mukai, "Phosphor-conversion white light emitting diode using InGaN near-ultraviolet chip," Jpn. J. Appl. Phys. 41, L371-L373 (2002).   DOI   ScienceOn
13 K. J. Choi, J. K. Park, K. N. Kim, C. H. Kim, and H. K. Kim, "Luminescence characteristics of $Ba^{2+}$ co-doped $Sr_2SiO_4$: Eu yellow phosphor for light emitting diodes," J. Korean Ceram. Soc. 43, 169-172 (2006) and references therein.   과학기술학회마을   DOI   ScienceOn
14 B. Chen, J. Jeong, M. Jayasimhadri, K. Jang, H. S. Lee, E. Cho, S. S. Yi, and J. H. Jeong, "Excitation-dependent emissive properties of silicate phosphor for light converted LEDs," J. Korean Phys. Soc. 55, 1587-1590 (2009).   과학기술학회마을   DOI   ScienceOn