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http://dx.doi.org/10.3807/KJOP.2014.25.4.216

Luminescence Characteristics of Blue Phosphor and Fabrication of a UV-based White LED  

Jung, Hyungsik (Department of Image Science and Engineering, Pukyong National University)
Park, Seongwoo (Department of Image Science and Engineering, Pukyong National University)
Kim, Taehoon (Lumimicro Co. Ltd.)
Kim, Jongsu (Department of Image Science and Engineering, Pukyong National University)
Publication Information
Korean Journal of Optics and Photonics / v.25, no.4, 2014 , pp. 216-220 More about this Journal
Abstract
We have synthesized a $CaMgSi_2O_6:Eu^{2+}$ blue phosphor via a solid-state reaction method. The $CaMgSi_2O_6:Eu^{2+}$ phosphor has monoclinic structure with a space group of C2/c (15), and an emission band peaking at 450 nm (blue) due to the $4f^7-4f^65d$ transition of the $Eu^{2+}ion$. The emission intensity at $100^{\circ}C$ is 54% of the value at room temperature. A white LED was fabricated by integrating a UV LED (400 nm) with our blue phosphor plus two commercial green and red phosphors. The white LED shows a color temperature of 3500 K with a color rendering index of 87 (x = 0.3936, y = 0.3605), and a luminous efficiency of 18 lm/W. The white LED shows a luminance maintenance of 97% after operation at 350 mA for 400 hours at $85^{\circ}C$.
Keywords
Blue phosphor; UV LED; Color rendering index; Color temperature;
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