Shang Mengmeng, Fan Jian, Lian Hongzhou, Zhang Yang, Geng Dongling, Lin Jun
State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, P. R. China.
Inorg Chem. 2014 Jul 21;53(14):7748-55. doi: 10.1021/ic501063j. Epub 2014 Jun 27.
The influence of Mg(2+)-Si(4+)/Ge(4+) incorporation into Ce(3+)-doped Y3Al5O12 garnet phosphors on the crystal structure and luminescence properties is described in this work. X-ray diffraction with Rietveld refinements, photoluminescence spectra, absolute quantum yield, thermal quenching behavior, and lifetimes were utilized to characterize samples. The introduction of Mg(2+)-Si(4+)/Ge(4+) leads to an obvious red shift of emission wavelength under the excitation of blue light, especially for the series of Mg(2+)-Si(4+) substitutions, which is suited for white light-emitting diodes (LEDs) with low color temperatures and good color rendering using only a single phosphor. More interestingly, an additional emission band locating at high-energy was observed with ultraviolet excitation, which is different than previous literature. Under the excitation of ultraviolet, the emission color for the Mg(2+)-Si(4+) substitutions can be tuned from yellow-green to blue, which is expected to obtain single-phased phosphors with white emission excited with UV-LED chip. The usual Ce(3+) emission band at low energy has stronger quenching at high temperatures. The mechanisms for the observed phenomena are discussed.
本文描述了将Mg(2+)-Si(4+)/Ge(4+)掺入Ce(3+)掺杂的Y3Al5O12石榴石荧光粉对晶体结构和发光性能的影响。利用带有Rietveld精修的X射线衍射、光致发光光谱、绝对量子产率、热猝灭行为和寿命来表征样品。Mg(2+)-Si(4+)/Ge(4+)的引入导致蓝光激发下发射波长明显红移，特别是对于一系列Mg(2+)-Si(4+)取代情况，这适用于仅使用单一荧光粉的低色温且显色性良好的白光发光二极管（LED）。更有趣的是，在紫外激发下观察到一个位于高能区的额外发射带，这与先前的文献报道不同。在紫外激发下，Mg(2+)-Si(4+)取代的发射颜色可从黄绿色调至蓝色，有望获得用紫外LED芯片激发产生白光发射的单相荧光粉。通常在低能量处的Ce(3+)发射带在高温下有更强的猝灭。文中讨论了观察到的这些现象的机制。
