標題: Crystal structure of blue-white-yellow color-tunable Ca4Si2O7F2:Eu2+,Mn2+ phosphor and investigation of color tunability through energy transfer for single-phase white-light near-ultraviolet LEDs
作者: Huang, Chien-Hao
Chan, Ting-Shan
Liu, Wei-Ren
Wang, De-Yin
Chiu, Yi-Chen
Yeh, Yao-Tsung
Chen, Teng-Ming
應用化學系
Department of Applied Chemistry
公開日期: 2012
摘要: The crystal structure of Ca4Si2O7F2:Eu2+,Mn2+ was refined and determined from X-ray diffraction (XRD) profiles obtained using a synchrotron light source by the Rietveld refinement method. It was found to crystallize into a monoclinic structure with the P2(1)/c(14) space group. On examining the Mn2+-concentration-dependent photoluminescence properties, we found that the emission colors could be tuned from blue (0.152, 0.112) to white-light (0.351, 0.332) and eventually to yellow (0.430, 0.423) through energy transfer by changing the Eu2+/Mn2+ ratio. Moreover, energy transfer from a sensitizer Eu2+ to an activator Mn2+ occurs via a resonance-type dipole-quadrupole interaction mechanism, and the critical distances of the energy transfer were calculated to be 11.66 angstrom and 12.61 angstrom using concentration quenching and spectral overlap methods, respectively. Combining a 400 nm near-ultraviolet (NUV) chip and a single-phase white-emitting (Ca0.96Eu0.01Mn0.03)(4)Si2O7F2 phosphor produced a white-light NUV LED with CIE chromaticity coordinates of (0.347, 0.338) and a warm color temperature of 4880 K.
URI: http://hdl.handle.net/11536/16967
http://dx.doi.org/10.1039/c2jm33160h
ISSN: 0959-9428
DOI: 10.1039/c2jm33160h
期刊: JOURNAL OF MATERIALS CHEMISTRY
Volume: 22
Issue: 38
起始頁: 20210
結束頁: 20216
顯示於類別:期刊論文


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