標題: (Ca,Mg,Sr)(9)Y(PO4)(7):Eu2+,Mn2+: Phosphors for white-light near-UV LEDs through crystal field tuning and energy transfer
作者: Huang, Chien-Hao
Wu, Pin-Jiun
Lee, Jyh-Fu
Chen, Teng-Ming
應用化學系
Department of Applied Chemistry
公開日期: 1-Jan-2011
摘要: Two series of single-composition (Ca,Mg,Sr)(9)Y(PO4)(7):Eu2+ and (Ca0.5Sr0.5)(9)Y(PO4)(7):Eu2+,Mn2+ phosphors were synthesized via high-temperature solid-state reactions. Their emission colors could be tuned from blue to green and eventually to red through tuning the crystal field splitting and energy transfer. On examining the Mn2+ concentration-dependent photoluminescence properties, we found that co-doping with Mn2+ would lead to a change in Eu2+/Eu3+ ratio. Moreover, an energy transfer from Eu2+ to Mn2+ occurs because of the spectral overlap between the emission band of Eu2+ and the excitation band of Mn2+. The resonance-type energy transfer via a dipole-quadrupole interaction mechanism was supported by decay lifetime data and the critical distance of energy transfer was calculated to be 11.09 angstrom A. A trichromatic white-light emitting diode was fabricated by integrating a 380 nm near-ultraviolet (n-UV) chip comprising yellow-emitting (Ca0.5Sr0.5)(9)Y (PO4)(7):0.007Eu(2+),0.02Mn(2+) and blue-emitting (Ca0.5Mg0.5)(9)Y(PO4)(7):0.007Eu(2+) phosphors into a single package. Such a composite device emitted white light with a correlated color temperature of 6303 K, a color rendering index of 87.4, and color coordinates (0.314, 0.348) close to those of ideal white light. The results suggest that a phosphor blend of (Ca0.5Sr0.5)(9)Y(PO4)(7):0.007Eu(2+), 0.02Mn(2+) and (Ca0.5Mg0.5)(9)Y(PO4)(7):0.007Eu(2+) is potentially useful for white n-UV light-emitting diodes (LEDs).
URI: http://dx.doi.org/10.1039/c1jm11018g
http://hdl.handle.net/11536/150344
ISSN: 0959-9428
DOI: 10.1039/c1jm11018g
期刊: JOURNAL OF MATERIALS CHEMISTRY
Volume: 21
起始頁: 10489
結束頁: 10495
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