Jong Su Kim

Optical and Structural Properties of Eu2 + -doped ( Sr1 − x Ba x ) 2SiO4 phosphors

Europium (Eu 2 + )-doped alkaline earth orthosilicates (Sr 1 - x Ba x ) 2 SiO 4 :Eu 2 + , are studied as a phosphor for color-tunable white-light-emitting diode. With an increase of Ba ions in (Sr 1 - x Ba x ) 2 SiO 4 :Eu 2 + , the lattice constants increase, and the emission bands shift to higher energy in a systematic way. This blueshift behavior can be clarified by crystal field strength. Also, the lattice vibration energies from Raman spectra decrease with an increase of Ba ions in (Sr 1 - x Ba x ) 2 SiO 4 :Eu 2 + . The emission-quenching temperature dependence of the lattice vibration frequency is investigated in terms of a well-known configurational coordinate diagram.

P‐201L: Late‐News Poster: Comparative Analysis on Thermal Properties of Y3Al5O12:Ce3+ and (Ba, Sr)2SiO4:Eu2+ Yellow Phosphors for White LED

The spectral variation of Y3Al5O12:Ce3+ (YAG) with temperature is smaller than that of its alternative (Ba, Sr) 2SiO4:Eu2 (BOS). The quenching temperature of YAG is higher than that of BOS. On the other hand, the luminance of YAG is seriously thermal-degraded in comparison with BOS.

P-203L: Late-News Poster: Thick Electroluminescent Device using ZnGa2O4:Mn2+ Ceramic Phosphor Film

Thick ZnGa2O4:Mn2+ Ceramic phosphor film is applied to A.C. inorganic electroluminescent (EL) device. The ceramic-film phosphor with 200 μm thick is sandwiched between transparent ITO glasses. The EL device under A.C. power of 200 V and 60 Hz shows the green emission spectrum from Mn2+ ions peaking at 508 nm.