Optical properties of eu doped M-Ga2S4 (M: Zn, Ca, Sr) phosphors for white light emitting diodes.
Eu2+ doped M-thiogallate (MGa2S4, M: Zn, Ca, Sr) phosphors were prepared by solid-state reaction. The dependence of luminescent properties, photoluminescence and cathodoluminescence, on M2+ ions was investigated. ZnGa2S4: Eu2+, CaGa2S4: Eu2+, and SrGa2S4: Eu2+ exhibited a green emission band at 540 nm, 560 nm, and 535 nm, respectively. The red-shift between CaGa2S4: Eu2+ and SrGa2S4: Eu2+ was originated from the radius difference of Ca2+ and Sr2+ ions. However, it did not apply to ZnGa2S4 : Eu2+ despite of smaller radius of Zn2+ ion. The particle size of ZnGa2S4 : Eu2+ was much smaller than those of the other thiogallates, leading to extremely low CL emission.
Department of Materials Science and Engineering, Kyonggi University, Suwon 443-760, Korea.
Joo Won
JW
Kim
Young Jin
YJ
Kim
D005063:Europium / Q000737:chemistry*; D005708:Gallium / Q000737:chemistry*; D008029:Lighting / Q000295:instrumentation / Q000379:methods*; D049408:Luminescent Agents / Q000737:chemistry*; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D055095:Optics and Photonics; D010316:Particle Size; D012666:Semiconductors
D049408:Luminescent Agents; D005063:Europium; D005708:Gallium