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稀土激发的锂硅酸盐发光特性研究(2)

时间:2021-08-26 20:50来源:毕业论文
In this study, Li2Sr0.9Mg0.1SiO4: Tb3+and Li2Sr0.9Mg0.1SiO4: Ce3+ were prepared by high temperature solid-state method. After several temperature selection, the final synthesis temperature is set at 8

In this study, Li2Sr0.9Mg0.1SiO¬4: Tb3+and Li2Sr0.9Mg0.1SiO¬4: Ce3+ were prepared by high temperature solid-state method. After several temperature selection, the final synthesis temperature is set at 850 degrees Celsius. Li2Sr0.9Mg0.1SiO¬4: Tb3+ is hexagonal. The photoluminescence (PLS) and fluorescence emission spectra (PL) were used to characterize the fluorescence properties of samples with different concentrations. Emission spectra and chromatograms show that the excitation wavelength of Li2Sr0.9Mg0.1SiO¬4: Tb3+is 292nm. The emission spectra show the emission of Tb3 + ions, with 488nm, 543nm (main peak), 584nm, 625nm four emission peaks. The chromaticity coordinates are x = 0.2993, y = 0.5321, and the emission color is green. The best value for Tb3 + doping concentration is 0.01 (atomic ratio 0.1%). By comparing the emission spectra of the samples with different doping concentrations, the concentration quenching point of the phosphor was found to be 0.01, and the main factors of concentration quenching were analyzed. The main factors of the quenching of Tb3 + Pole - quadrupole electronic interaction. When the UV light source is turned off, the Li2Sr0.9Mg0.1SiO¬4: Tb3+ phosphor exhibits a typical afterglow behavior. After fitting the experimental data, a typical triple exponential decay behavior is shown. The study of thermoluminescence further shows that the afterglow behavior of Tb3 + phosphors is due to the combination of electrons generated by valence band and rare earth ions (Tb3+) doped Li2Sr0.9Mg0.1SiO¬4, Li2Sr0.9Mg0.1SiO¬4: Tb3+ phosphors have excellent afterglow performance due to the increase in trap concentration due to the addition of Tb3+ ions, thereby increasing the persistence length. Emission spectra and chromatograms show that the excitation wavelength of Li2Sr0.9Mg0.1SiO¬4: Tb3+ is 277nm. The emission spectra show the emission of Tb3+ ions, with 391nm, 416nm (main peak) and two emission peaks. Chromaticity coordinates x = 0.1584, y = 0.0338, light color is blue. The best Ce3+ doping concentration is 0.004. By comparing the emission spectra of the samples with different doping concentrations, the concentration quenching point of the phosphor was found to be 0.01, and the main factors of concentration quenching were analyzed. The main factors of the quenching of Ce3 + Pole - quadrupole electronic interaction. When the UV light source is turned off, the Li2Sr0.9Mg0.1SiO¬4: Ce3+ phosphor exhibits a typical afterglow behavior. After fitting the experimental data, a typical triple exponential decay behavior is shown. The study of thermoluminescence further shows that the afterglow behavior of Ce3+ phosphors is due to the combination of electrons generated by valence band and rare earth ions (Ce3+) doped Li2Sr0.9Mg0.1SiO¬4, Li2Sr0.9Mg0.1SiO¬4: Ce3+ phosphors have excellent afterglow performance due to the increase in trap concentration due to the addition of Ce3+ ions, thereby increasing the afterglow length.

Key words: long afterglow; Li2Sr0.9Mg0.1SiO¬4; solid-phase reaction traps; spectra; traps

目录

1.绪论 1

1.1引言 1

1.2长余辉材料的基本简介 1

1.2.1铝酸盐基的发光材料 1

1.2.2硅酸盐基的发光材料 2

1.2.3长余辉材料的发展现状及应用 2

1.3长余辉材料的发光机理 4

1.3.1空穴传输模型 6

1.3.2位移坐标模型 6

1.4长余辉材料的合成方法 7

1.4.1高温固相法 7

1.4.2溶胶-凝胶法 8

1.4.3燃烧法 稀土激发的锂硅酸盐发光特性研究(2):http://www.youerw.com/cailiao/lunwen_80970.html

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