| Summary: | 碩士 === 國立交通大學 === 應用化學系所 === 95 === In this research we have synthesize nine different types of Eu2+-or Ce3+-doped phosphors with the compositions of Host：Eu2+(or Ce3+) (Host = A、B、C、D、E、F、G、H、I ) under a mildly reducing atmosphere. Each of these compounds was solely doped with Ce3+ or Eu2+,which are expected to substitute for the positions of Ca2+、Sr2+、Ba2+,respectively. By comparing X-ray data of the samples to those reported in database, we are sure that the crystal structures of hosts do not change after doping of 2% rare earth ions. Through the measurements of diffuse reflectance spectrum for both doped and un-doped samples, we found that all of the optical emissions were resulted from the doped rare earth ions. We have also analyzed the structure of the hosts and made attempts to correlate the luminescence behaviors and crystal structure. In this phosphors synthesized in this work, rare-earth ions were found to substitute and enter the cation sites with six to twelve coordination number. The emission wavelength were found to vary from 323 nm to 506 nm as in the case of Ce3+-doped phosphors and 398 nm to 657 nm as in Eu2+-doped phosphors. Additionally, the C.I.E. chromaticity coordinates show that these phosphors emit hues including violet, blue, aqua blue, green, yellow and orange.
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