【作者】 刘春梦； 马崇庚； Mikhail G.Brik； 匡小军； 黄艳； 陶冶； 梁宏斌；

【Author】 Chunmeng Liu;Chonggeng Ma;Mikhail G.Brik;Xiaojun Kuang;Yan Huang;Tao Ye;Hongbin Liang;School of Chemistry and Chemical Engineering,Sun Yat-sen University;College of Sciences,Chongqing University of Posts and Telecommunications;Institute of Physics,University of Tartu,Ravila 14C,Tartu 50411,Estonia;Beijing Synchrotron Radiation Facility,Institute of High Energy Physics,Chinese Academy of Sciences;

【机构】 中山大学化学与化学工程学院； 重庆邮电大学理学院； Institute of Physics,University of Tartu,Ravila 14C,Tartu 50411,Estonia； 中国科学院高能物理研究所；

【摘要】 采用高温固相法合成了系列Sr8(Si4O12)Cl8:Ce3+/Eu2+荧光粉。根据X-射线粉末衍射数据进行Rietveld结构精修确定了Sr37.99Ce0.01(Si4O12)Cl8的结构及Ce+周围的配位环境,通过VUV-vis光谱和荧光衰减曲线表征了Sr8(Si4O12)Cl8:Ce3+的发光性质,并讨论了Ce3+在Sr8(Si4O12)Cl8基质中占据一个低对称性(C1)格位的晶体场劈裂情况。根据不同温度下Sr8(Si4O12)Cl8:Ce3+的发射光谱由Arrhenius公式拟合得到Ce3+最低5d轨道与基质导带底之间的能隙,推测出Ce3+能级相对于Sr8(Si4O12)Cl8基质的价带和导带的位置。Sr8(Si4O12)Cl8:Ce3+,Eu2+样品的VUV-vis光谱,荧光衰减曲线及量子效率均显示Ce3+可以有效地敏化Eu2+,Ce3+向Eu2+的能量传递效率随Eu2+掺杂量的增加而增大,Ce3+→Eu2+能量传递的临界距离为~23.07。更多还原

【Abstract】 A series of Sr3+8(Si4O12)Cl8:Ce/Eu2+ phosphors were prepared by a high-temperature solid-state method. The crystal structure of Sr8(Si4O12)Cl8:Ce3+ and the coordination environments around Ce3+ were determined from Rietveld refinement based on the X-ray diffraction data. The luminescence characteristics of Sr8(Si4O12)Cl8:Ce3+ were defined with VUV-vis spectra as well as fluorescence decays, and discussed in terms of crystal field splitting(CFS) in a low-symmetry(C1) site of Sr8(Si4O12)Cl8. The energy level diagram of CFS Ce3+ 5d with respect to the valence and conduction bands of the Sr8(Si4O12)Cl8 is estimated from the temperature dependence of the emission intensities. Moreover, Ce3+ can efficiently sensitize the luminescence of Eu2+ in Sr8(Si4O12)Cl8, as observed by measuring the photoluminescence properties, fluorescence decays and quantum efficiency of Sr8(Si4O12)Cl8:Ce3+, Eu2+. The electric dipole-electric dipole transfer of Ce3+→Eu2+ has an efficiency of 90 % with a critical distance of ~23.07?.更多还原