Title page for etd-0720110-001152


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URN etd-0720110-001152
Author Cheng-hsun Chung
Author's Email Address No Public.
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Department Electro-Optical Engineering
Year 2009
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title The Study of Ce:YAG Doped Glass Fabrication and Reliability Tests in High-Power White Light-Emitting-Diodes
Date of Defense 2010-06-25
Page Count 100
Keyword
  • white-light
  • high-power
  • LED
  • glass phosphor
  • reliability
  • Abstract High thermal stability and humidity resistance of phosphor-converted white-light-emitting diodes (PC-WLEDs) using Ce:YAG doped glass, instead of conventional Ce:YAG doped silicone, as a phosphor-converted layer is proposed and fabricated. The glass has five times higher glass transition temperature (Tg) of 750℃ compare with silicone of 150℃, that could exhibited better performance than silicone, including lumen loss, chromaticity shift, transmittance loss, and peak emission intensity undergoing three industry-standard reliability tests at either high (8wt%) or low (2wt%) doping concentrations of Ce:YAG. The proposed glass phosphor possesses host stability as glass and retains desired fluorescence as Ce:YAG.
    In thermal aging, thermal shock, and damp heat reliability results, the thermal aging has the largest degradation of lumen loss, but the results showed better thermal stability that the glass phosphor with 22~30% lumen loss improvement for 2~8 wt% Ce:YAG doping than silicone phosphor. The damp heat test has the largest degradation of chromaticity shift, but the results showed excellent humidity resistance that the glass phosphor with highest 49~65% chromaticity shift improvement for 2~8 wt% Ce:YAG doping than silicone phosphor. But under thermal shock test, there isn’t a large difference between glass and silicone phosphor. In this study, we demonstrate the feasibility of adapting glass as a phosphor-converted layer in PC-WLED module that can potentially provide higher reliability and better performance for high-power LEDs, particularly in the area where strict reliability is highly required and in the environment where silicone does not stand for long.
    Advisory Committee
  • Jao-Hwa Kuang - chair
  • Jiang-Jen Lin - co-chair
  • Ray-Hua Horng - co-chair
  • Jimmy Wang - co-chair
  • Wood-Hi Cheng - advisor
  • Files
  • etd-0720110-001152.pdf
  • indicate in-campus access in a year and off_campus not accessible
    Date of Submission 2010-07-20

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