【作者】 林茂；

【导师】 马丽景；

【作者基本信息】 北京化工大学 ， 工业催化， 2004， 硕士

【摘要】 对许多稀土离子和过渡金属离子而言，Zn2SiO4是一种非常合适的基质，掺杂后能够发出高效荧光。Zn2SiO4:Mn具有良好的化学稳定性和抗潮性，能发出高色纯度的绿色荧光，使其成为最有希望取代传统场致发光设备荧光粉的材料之一，近年来在低压放射线照相术和荧光透视法等医学成像方面也得到了广泛的应用。本文首先研究了Zn2SiO4:Mn的焙烧行为。采用溶胶－凝胶法制备的干凝胶在1100℃下焙烧2h后可以得到具有良好晶型的产物。为了减少在干燥过程中的团聚现象，分别采用常规干燥法、超临界干燥法和共沸蒸馏法处理干凝胶。其中采用共沸蒸馏法制备的产物为粒径分布在60~160nm之间的不规则球形颗粒，具有良好的荧光效果。本文还研究了掺杂对Zn2SiO4荧光效果的影响。在240nm的紫外激发下，样品可以发出可见光范围内的绿色荧光，其波长为525nm。双掺杂的Zn2SiO4激发光谱和发射光谱跟单掺杂相比并无改变。摩尔配比为Zn2+:Mn2+:Er3+＝0.956: 0.043: 0.001时具有最佳的荧光效果，在纳米级的颗粒范围内获得了接近商业粉的荧光亮度。此外还尝试了水热法制备Zn2SiO4:Mn。在水热反应釜内，250℃，3.97MPa的条件下，无需高温焙烧即可得到Zn2SiO4晶体，具有良好的<WP=4>长针形貌，但荧光效果不尽如人意。更多还原

【Abstract】 Zn2SiO4 has been identified as a very suitable host matrix for many rare earth and transition metal dopant ions for the efficient luminescence. A prominent green emission color has been reported on Zn2SiO4:Mn, it’s one of the most promising alternatives to the traditional phosphors in electroluminescent devices for it’s chemical and moisture stability property. Recently, Zn2SiO4:Mn phosphor was evaluated for use in medical imaging technology, and it was found to be appropriate for low-voltage radiography and fluoroscopy。The sinter property was studied first. Prepared by Sol-Gel method, the xerogel fired at 1100℃ for 2h was well crystallized. A series of drying method as regular method, supercritical drying method and heterogeneous distillation method was used. The phosphors prepared by heterogeneous distillation were composed of small irregular round-shaped grains which were about 60~160nm, shows bright green emission band at 525nm.In this paper, we also study the relationship between luminescent intensity and dopant concentration. With the ultraviolet excitation at 240nm, <WP=6>the phosphor can emit bright green luminescent at 525nm. The co-activated phosphor shows same excitation spectrum and emission spectrum with Mn-doped Zn2SiO4. The optimized dopant ratio(mol) is Zn2+: Mn2+: Er3+＝0.956:0.043:0.001. The nano-scale powder shows luminescent intensity approximate to the commercial powder.Furthermore, we used hydrothermal method to prepare Zn2SiO4:Mn. Under the pressure of 2.97MPa, the reaction was carried out in a autoclave at temperature of 250℃. This method can form crystallized Zn2SiO4 without high temperature sintering. The powder has not good emission intensity but good acicular morphology.更多还原