UV 기반 백색 LED용 청색 형광체의 발광특성 및 백색 LED 제조

We have synthesized a CaMgSi 2 O 6 :Eu 2+ blue phosphor via a solid-state reaction method. The CaMgSi 2 O 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℃ 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℃.

[1]  Tao Wang,et al.  1 mW AlInGaN-based ultraviolet light-emitting diode with an emission wavelength of 348 nm grown on sapphire substrate , 2002 .

[2]  B. Henderson,et al.  Optical spectroscopy of inorganic solids , 1989 .

[3]  G. Blasse,et al.  Luminescence of Eu2+ in barium and strontium aluminate and gallate , 1995 .

[4]  T. Barry.  Fluorescence of Eu2+‐Activated Phases in Binary Alkaline Earth Orthosilicate Systems , 1968 .

[5]  G. Blasse,et al.  The influence of the host lattice on the luminescence of divalent europium , 1997 .

[6]  K. Kimoto,et al.  Characterization and properties of green-emitting β-SiAlON:Eu2+ powder phosphors for white light-emitting diodes , 2005 .

[7]  G. Blasse,et al.  Luminescence of Eu2+ in silicate host lattices with alkaline earth ions in a row , 1996 .

[8]  P. Dorenbos.  The 4fn↔4fn − 15d transitions of the trivalent lanthanides in halogenides and chalcogenides , 2000 .

[9]  Htjm Bert Hintzen,et al.  Luminescence properties of Eu2+ - activated alkaline-earth silicon-oxynitride MSi2O2-deltaN2+2/3delta (M = Ca, Sr, Ba) : A promising class of novel LED conversion phosphors , 2005 .

[10]  Sue-Lein Wang,et al.  Direct white light phosphor: a porous zinc gallophosphate with tunable yellow-to-white luminescence. , 2005, Journal of the American Chemical Society.

[11]  T. Barry.  Equilibria and Eu2+ Luminescence of Subsolidus Phases Bounded by Ba3MgSi2 O 8, Sr3MgSi2 O 8, and Ca3MgSi2 O 8 , 1968 .

[12]  D. Jeon,et al.  Origin of PL intensity increase of CaMgSi2O6 : Eu2+ phosphor after baking process for PDPs application , 2005 .

[13]  N. Hirosaki,et al.  Luminescence Properties of a Red Phosphor, CaAlSiN3 : Eu2 + , for White Light-Emitting Diodes , 2006 .