JOURNAL OF THE ILLUMINATING ENGINEERING INSTITUTE OF JAPAN
Online ISSN : 1349-838X
Print ISSN : 0019-2341
ISSN-L : 0019-2341
Volume 93 , Issue 11
Showing 1-9 articles out of 9 articles from the selected issue
Special Issue Papers : Development Technologies Related to Emissive and Non-Emissive Displays
  • Shuhei Yamauchi, Takeshi Fukuda, Zentaro Honda, Naoto Kijima, Norihiko ...
    2009 Volume 93 Issue 11 Pages 790-793
    Published: November 01, 2009
    Released: April 23, 2010
    JOURNALS FREE ACCESS
    We demonstrated an improved durability of Eu(HFA)3(TPPO)2 [tris(hexafluoroacetylacetonato)- europium(III) 1,2-phenylenebis(diphenylphosphine oxide)] encapsulated by a sol-gel derived silica glass film. The film was constructed using phenyltrimethoxysilane and diethoxy- dimethylsilane as a starting solution. Unlike cases in which conventional tetramethoxysilane is used, no decrease in internal quantum efficiency was observed at room temperature. We further improved the thermal and long-term stability of Eu(HFA)3(TPPO)2 inside the transparent glass film at elevated annealing temperatures when compared to the Eu(HFA)3(TPPO)2 powder itself: The photoluminescence quantum efficiency of the transparent film was 60% at 160°C and 32% at 20°C. Properly prepared glass networks protect the Eu chelate from free oxygen and water in the transparent glass film, which is promising for future practical applications.
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  • Zentaro Honda, Takeshi Fukuda, Norihiko Kamata
    2009 Volume 93 Issue 11 Pages 794-797
    Published: November 01, 2009
    Released: April 23, 2010
    JOURNALS FREE ACCESS
    Organic-inorganic hybrids based on the layered perovskite framework ([CH3(CH2)17NH2]2PbI4 and [CH3(CH2)17NH2]2PbCl4) have been naturally formed by intercalating lead hallide into organic (alkylammine) Langmuir-Blodgett films. Only diffraction peaks corresponding to (0 0 n) of the layered perovskite were observed in the X-ray diffraction pattern of the deposited film. X-ray diffraction measurement demonstrated that the layer structure is oriented parallel to the film plane. The deposited film showed sharp and strong UV-Vis absorption at 390 nm, which is charactristic of Wannier exciton in lead halide-alkylammonium multi-layered perovskites, thus demonstrating the formation of the layered perovskite structure.
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  • Toshikatsu Sakai, Katsu Tanaka, Shinji Okamoto
    2009 Volume 93 Issue 11 Pages 798-801
    Published: November 01, 2009
    Released: April 23, 2010
    JOURNALS FREE ACCESS
    Bi-activated SrGa2S4 (SrGa2S4:Bi) phosphor exhibits green luminescence with a peak wavelength of 533 nm and a full width half maximum of 58 nm. This luminescence is attributed to the 6p-6s transition in the 6s2 configuration of Bi3+. As SrGa2S4 is co-activated by the Bi3+ and Mn2+ ions, the excitation band around 400 nm is enhanced relative to that around 300 nm. Since the PL properties of SrGa2S4:Bi were similar to those of SrGa2S4:Eu, the SrGa2S4:Bi phosphors are potential alternatives to SrGa2S4:Eu phosphors.
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  • Hiroko Kominami, Shinji Yamashita, Yoichiro Nakanishi, Kazuhiko Hara, ...
    2009 Volume 93 Issue 11 Pages 802-806
    Published: November 01, 2009
    Released: April 23, 2010
    JOURNALS FREE ACCESS
    White light emitting diodes (LEDs) are expected to be used as lighting of the next generation for, for example, headlights, back lighting of liquid crystal displays (LCDs), illuminations, and so on. However, red emitting phosphors used for white LEDs have lower luminance efficiency than other emitting color phosphors because of larger stokes shift. La2O2S:Eu is known as red emitting phosphor; it shows good luminescence under near-ultraviolet excitation. In this study, synthesis of La2O2S:Eu using the citric acid gel method has been investigated. The results show that the particle size can be controlled by changing pre-firing conditions.
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Original Papers
Research Note
  • Yoshikazu Araki, Masayuki Sakano, Teruaki Kumaki, Daisuke Tanaka, Yuta ...
    2009 Volume 93 Issue 11 Pages 838-842
    Published: November 01, 2009
    Released: April 23, 2010
    JOURNALS FREE ACCESS
    The authors have constructed a simultaneous multi-point illuminance measurement system to measure illuminance. The functions of this system include environment measurement, signal transmission via wired and wireless networks, and data analysis. The system contains a control PC and a control module. The control module is made up of the voltage supply, the communication part, and the measuring module, which includes the illuminance meters. Measured values are converted from analogue to digital signals, and they are transmitted to the control PC through both the wired and wireless LAN systems. The operating system of the control PC is Wmdows 2000 and the controlling software is Visual Basic 6.0. The authors will discuss the measurement results (which are now applicable) of the following illuminances: continuing long time and maximum and simultaneous multi-points.
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