The fluorescent characteristic and emission spectra of Eu^(2+) in the cubic structure Ca_8Zn(SiO_4)_4Cl_2 with three kinds of cation sites is reported.The influence of temperature,Eu^(2+) concentra- tion and excitatio...The fluorescent characteristic and emission spectra of Eu^(2+) in the cubic structure Ca_8Zn(SiO_4)_4Cl_2 with three kinds of cation sites is reported.The influence of temperature,Eu^(2+) concentra- tion and excitation conditions on fluorescent properties of Eu^(2+) are studied at 77 and 298 K.The coordination number of Eu^(2+) at different sites is obtained.The green and red emission bands arise from Eu_(2+) ions locating on eight- and six- coordinated inequivalent sites respectively.展开更多
A yellow phosphor, Ca2BO3CI：Eu2＋, is prepared by the high-temperature solid-state method. Under the condition of excitation sources ranging from ultraviolet to visible light, efficient yellow emission can be observe...A yellow phosphor, Ca2BO3CI：Eu2＋, is prepared by the high-temperature solid-state method. Under the condition of excitation sources ranging from ultraviolet to visible light, efficient yellow emission can be observed. The emission spectrum shows an asymmetrical single intensive band centred at 573 nm, which corresponds to the 4f65dl→4f7 transition of Eu2＋. Eu2＋ ions occupy two types of Ca2＋ sites in the Ca2BO3C1 lattice and form two corresponding emission centres, respectively, which lead to the asymmetrical emission of Eu2＋ in Ca2BO3C1. The emission intensity of Eu2＋ in Ca2BO3C1 is influenced by the Eu2＋ doping concentration. Concentration quenching is discovered, and its mechanism is verified to be a dipole-dipole interaction. The value of the critical transfer distance is calculated to be 2.166 nm, which is in good agreement with the 2.120 nm value derived from the experimental data.展开更多
文摘The fluorescent characteristic and emission spectra of Eu^(2+) in the cubic structure Ca_8Zn(SiO_4)_4Cl_2 with three kinds of cation sites is reported.The influence of temperature,Eu^(2+) concentra- tion and excitation conditions on fluorescent properties of Eu^(2+) are studied at 77 and 298 K.The coordination number of Eu^(2+) at different sites is obtained.The green and red emission bands arise from Eu_(2+) ions locating on eight- and six- coordinated inequivalent sites respectively.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10974013, 60978060, and 10804006)the Research Fund for the Doctoral Program of Higher Education, China (Grant No. 20090009110027)+5 种基金the Beijing Municipal Natural Science Foundation, China (Grant No. 1102028)the National Basic Research Program of China (Grant No. 2010CB327704)the National Natural Science Foundation for Distinguished Young Scholars (Grant No. 60825407)the Beijing Municipal Science and Technology Commission, China (Grant No. Z090803044009001)the Science Fund of the Key Laboratory of Luminescence and Optical Information, Beijing Jiaotong University, Ministry of Education, China (Grant No. 2010LOI12)the Excellent Doctor's Science and Technology Innovation Foundation of Beijing Jiaotong University, China (Grant No. 2011YJS073)
文摘A yellow phosphor, Ca2BO3CI：Eu2＋, is prepared by the high-temperature solid-state method. Under the condition of excitation sources ranging from ultraviolet to visible light, efficient yellow emission can be observed. The emission spectrum shows an asymmetrical single intensive band centred at 573 nm, which corresponds to the 4f65dl→4f7 transition of Eu2＋. Eu2＋ ions occupy two types of Ca2＋ sites in the Ca2BO3C1 lattice and form two corresponding emission centres, respectively, which lead to the asymmetrical emission of Eu2＋ in Ca2BO3C1. The emission intensity of Eu2＋ in Ca2BO3C1 is influenced by the Eu2＋ doping concentration. Concentration quenching is discovered, and its mechanism is verified to be a dipole-dipole interaction. The value of the critical transfer distance is calculated to be 2.166 nm, which is in good agreement with the 2.120 nm value derived from the experimental data.
