Current Optics and Photonics

Optical Society of Korea (한국광학회)
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Effect of Red-emitting Sr2.41F2.59B20.03O74.8:Eu0.12,Sm0.048 Phosphor on Color Rendering Index and Luminous Efficacy of White LEDs

  • Nguyen, Anh Q.D. (Nguyen Tat Thanh University) ;
  • Nguyen, Vinh H. (Nguyen Tat Thanh University) ;
  • Lee, Hsiao-Yi (Department of Electrical Engineering, National Kaohsiung University of Applied Sciences)
  • Received : 2016.11.12
  • Accepted : 2017.01.31
  • Published : 2017.04.25
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Abstract

Color rendering index (CRI) and luminous efficacy (LE) are two key performance factors of white LEDs (WLED). While most recent works in optics focus on methodology to improve these factors, little attention has been dedicated to chemical composition of materials. This paper studies the effect of $Sr_{2.4}1F_{2.59}B_{20.03}O_{74.8}:Eu_{0.12},Sm_{0.048}$ phosphor (SrSm), in terms of concentration and particle size on CRI and LE of 8500 K - WLEDs. Importantly, the molar mass of the componential ions in SrSm are calculated to shed light on the connection between the chemical composition of the material of interest and the performance of WLEDs. Results show that CRI can be improved to a value of around 86 by boosting red-light components in WLEDs, for all 3 major configurations: conformal, in-cup, and remote phosphor. CRI value tends to decrease with larger size of particles, while LE value goes in the reverse direction. On the other hand, both CRI and LE appear to be reduced at higher concentration of SrSm. This light attenuation is analyzed by using the Lambert-Beer law and Mie-scattering theory.

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References

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