【作者】 许潮发；

【导师】 刘晓华；

【作者基本信息】 汕头大学 ， 材料物理与化学， 2010， 硕士

【摘要】 采用水热法制备了共掺杂的全色Zn2SiO4:Ti, Mn, Eu发光粉,SnO2:Eu3+纳米晶,ZnO:Eu3+(0.5.at.%)纳米晶。采用X射线衍射仪(XRD),荧光光谱仪进行分析,研究了发光粉的晶体结构和发光性质。采用水热法制备了不同掺杂浓度的Zn2SiO4:Ti, Mn, Eu系列荧光粉,不同掺杂浓度的Zn2-xSiO4:xTi4+系列荧光粉以及白色荧光粉Zn2SiO4:Ti, Mn, Eu系列。XRD表明样品均为纯相硅锌矿结构的Zn2SiO4。荧光光谱检测表明:Zn2-xSiO4:xMn2+系列发光粉的激发谱由Zn2SiO4基质吸收带和Mn2+的电荷迁移带组成,发射谱由Mn2+的4T1-6A1跃迁发射形成,Zn2-xSiO4:xMn2+发光强度随Mn2+掺杂浓度增加而增强,当样品掺杂浓度高于3.0 at.%时出现浓度淬灭。Zn2-xSiO4:xTi4+系列样品的激发谱由属于Ti4+电荷迁移带的宽激发带组成,发射光谱起源于Ti4+的2E-1T跃迁。当Ti4+掺杂浓度在2.5at.%时出现浓度淬灭。通过对不同掺杂离子浓度的调节,实现了En, Mn, Ti共掺杂Zn2SiO4发光粉的白光发射。采用水热法合成了SnO2:Eu3+纳米晶,并在不同温度下对此样品进行热处理。XRD表明实验制备得到的样品均为纯相金红石结构的SnO2。样品的颗粒随热处理温度的升高而增大。光谱研究表明,热处理后的样品激发谱中除含有Eu3+的f-f跃迁的特征激发峰外还有O2--Eu3+电荷迁移带,但未经热处理的样品不出现电荷迁移带,发光强度热处理温度成反比。采用水热法合成了ZnO:Eu3+(0.5.at.%)纳米晶,通过改变实验条件实现了纳米晶尺寸的完全可控。XRD分析表明样品均为纯相纤锌矿结构的ZnO。颗粒越小,样品的发光强度越大,经过热处理后,ZnO:Eu3+(0.5.at.%)纳米晶发光强度明显减弱,发射峰产生红移。更多还原

【Abstract】 The full-color emitting Zn2SiO4:Ti, Mn, Eu phosphors, red-emitting SnO2:Eu3+and ZnO:Eu3+ nanocrystals were prepared by hydrothermal method. The phosphor crystal structures were analysised by X-ray diffraction (XRD) and their optical properties were studied by PL.The crystal structures of the Zn2SiO4:Ti, Mn, Eu phosphors prepared by hydrothermal method with different conditions show the same pure Zn2SiO4 structure. The excitation spectra of Zn2-xSiO4:x Mn are consist of an intense charage transfer band and host absorption. The PL spectra, excited at 247 nm, are consist of the 4T1-6A1 emission transitions of Mn2+. The PL intensities of the phosphors are dependent on Mn2+ concentration and quenched for the Mn2+concentration of 3.0 at.%. The excitation spectra of Zn2-xSiO4:x Ti4+ is consist of an intense O2--Ti4+charage transfer band and the PL spectra , excited at 220 nm, are consist of the 2E-1T emissions of Ti4+. Their PL intensity are dependent on Ti4+ concentration and quenched for the Ti4+concentration of 2.5 at.%. The white light-emitting phosphors obtained by codoping Ti, Mn and Eu in Zn2SiO4.SnO2:Eu3+ nanophosphors were prepared by hydrothermal method. XRD analysis showed the formation of pure tetragonal rutile crystalline phase of tin oxide. Some samples were sintered at different temperatures. The sizes of SnO2:Eu3+ nanocrystals grew bigger when heat treatment temperature increased. The PL intensities of SnO2:Eu3+ nanocrystal are reduced by the heat treatment. The excitation spectra of SnO2:Eu3+ nanocrystal are consist of f-f transitions of Eu3+.ZnO:Eu3+ nanophosphors were prepared by hydrothermal method. XRD analysis showed the formation of pure wurtzite crystalline phase of zinc oxide. The ZnO:Eu3+ nanocrystals with the different sizes can be obtained by controlling Zn2+ concentration. we found that the smaller the size of the ZnO:Eu3+ nanophosphor the stronger the light emission. The PL intensities of the ZnO:Eu3+ nanophosphors decrease significantly with the heat treatment. There is the red shift of emission peak at 699nm after the heat treatment.更多还原