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Analysis of Luminous Characteristics of White LEDs Depending on Yellow Phosphors

황색 형광체의 종류에 따른 백색 LED 광원의 발광 특성 분석

  • 최현우 (한림대학교 전자물리학과) ;
  • 고재현 (한림대학교 전자물리학과)
  • Received : 2013.03.05
  • Accepted : 2013.04.01
  • Published : 2013.04.25

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.

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  2. Aging-Time Dependence of Color Rendering Index of a LED Lamp for Lighting vol.28, pp.3, 2014, https://doi.org/10.5207/JIEIE.2014.28.3.001
  3. Temperature Effect on the Optical Properties of YAG and Silicate Phosphor-based White Light Emitting Diodes vol.24, pp.3, 2013, https://doi.org/10.3807/KJOP.2013.24.3.135
  4. Effect of PVA Polymerization on Synthesis of YAG:Ce3+Phosphor Powders Prepared by a Solid-liquid Hybrid Route vol.51, pp.5, 2014, https://doi.org/10.4191/kcers.2014.51.5.424