【作者】 王兰兰；

【导师】 匡少平；

【作者基本信息】 青岛科技大学 ， 应用化学， 2011， 硕士

【摘要】 稀土发光材料是重要的稀土新材料,它在LED照明、信息显示和信息传递等领域都有广泛的应用。本课题采用表面活性剂辅助的共沉淀法,选取铝酸锌和铝酸镧两种材料为发光基质,以Eu³⁺和Tb³⁺为发光中心进行一系列研究。第一,采用十六烷基三甲基溴化铵辅助的共沉淀法制备掺Eu³⁺铝酸锌系列荧光粉,并对其晶体结构、粒径和发光性能进行研究。合成产物为立方晶系的ZnAl₂O₄: Eu³⁺,单胞分子数Z = 8。随着煅烧温度的增加,ZnAl₂O₄: Eu³⁺的结晶度增加,粒径增大,当煅烧温度达到700°C时,能够形成良好晶面。产物的发光以616 nm的5D0→7F2红光发射为主。当煅烧温度为800°C、Eu³⁺掺杂浓度为5%时,合成的ZnAl₂O₄: Eu³⁺荧光粉的发光强度最强,此时得到的荧光粉的色坐标为x = 0.6513,y = 0.3415。第二,采用聚乙二醇200辅助的共沉淀法制备掺Tb³⁺铝酸锌系列荧光粉,并进行XRD、TG-DTA分析和荧光测试。合成产物为立方晶系的ZnAl₂O₄: Tb³⁺,形成良好晶体的最佳煅烧温度是700°C。当Tb³⁺的掺杂浓度低于5%时,结晶度高,当高于5%时,结晶度减小。发光以544 nm处的绿光发射为主,它归属于Tb³⁺的5D4→7F5跃迁。当煅烧温度为600°C、Tb³⁺掺杂浓度为5%时,合成的ZnAl₂O₄: Tb³⁺荧光粉的发光强度最强。第三,采用十六烷基三甲基溴化铵辅助的共沉淀法制备制备掺Eu³⁺铝酸镧系列荧光粉,并对其晶体结构、粒径、发光情况和发光性能进行研究。当煅烧温度在为500°C⁸00°C时,合成产物是属于赝立方结构的LaAlO₃:Eu³⁺,随着煅烧温度增加,LaAlO₃: Eu³⁺的衍射峰强度增强,粒径增大。当煅烧温度为900°C时,所得样品开始有杂相La10Al4O21出现。当Eu³⁺掺杂浓度从4%增加到7%时,LaAlO₃: Eu³⁺的晶体结构没有太大的变化。产物的发光以617 nm的5D0→7F2红光发射为主。当煅烧温度为800°C时,合成的LaAlO₃:Eu³⁺荧光粉的发光强度最强。更多还原

【Abstract】 Rare-earth luminescent materials have attracted a lot of attention because of their application in LED lighting, information display, information transmission and so on. In this paper, ZnAl₂O₄: Eu³⁺, ZnAl₂O₄: Tb³⁺ and LaAlO₃: Eu³⁺ phosphors were obtained through the surfactant-assisted coprecipitation method. Structural and optical properties phosphors at different doping concentrations and annealed temperatures were mainly studied.1. ZnAl₂O₄: Eu³⁺ phosphors were synthesized through the CTAB-assisted coprecipitation method and characterized by XRD, SEM and photoluminescence （PL）. Products belong to clinic system and Z = 8. X-ray diffraction showed that the crystallization properties of ZnAl₂O₄: Eu³⁺ is perfect at low-doped concentration, yet the concentration is higher than 5%, the quality of crystallization decreases. Furthermore, higher temperature would enhance the crystallization properties of phosphors and could increase the particle size. When the annealed temperature is 700°C, a good crystallization has formed. The measurements reported that the lighting of ZnAl₂O₄: Eu³⁺ is mainly red, the dominant wavelength is 616 nm attributing to 5D0→7F2 transfer. When the annealed temperature is 800°C and doped concentration is 5%, ZnAl₂O₄: Eu³⁺ phosphor has the highest PL intensity and its chromaticity coordinate is x = 0.6513,y = 0.3415.2. ZnAl₂O₄: Tb³⁺ phosphors were prepared through the PEG200-assisted coprecipitation method and characterized by XRD, TG-DTA and photoluminescence. Products were ZnAl₂O₄: Tb³⁺ phosphors which belong to clinic system. When the annealed temperature is 700°C, a good crystallization has formed. When the concentration is higher than 5%, the quality of crystallization would decrease. PL analysis showed that the lighting of ZnAl₂O₄: Tb³⁺ is mainly green, the dominant wavelength is 544 nm attributing to 5D4→7F5 transfer of Tb³⁺. PL intensity of ZnAl₂O₄: Tb³⁺ reaches a maximum value at doped concentration around 5% annealed at 600°C.3. LaAlO₃: Eu³⁺phosphors were prepared through the CTAB-assisted coprecipitation method and characterized by XRD, SEM and PL. Products were LaAlO₃:Eu³⁺ phosphors which belong to rhombohedral system at 500°C⁸00°C. Higher temperature would enhance the crystallization properties of phosphors and could increase the particle size. When the temperature is 900°C, the impurity phase La10Al4O21 began to form. Doped concentration has little influence in the crystalline phase. The result showed that that the lighting of LaAlO₃:Eu³⁺ is mainly red, the dominant wavelength is 617 nm attributing to 5D0→7F2 transfer. PL intensity reaches a maximum value at doping concentration around 4% annealed at 800°C.更多还原