【作者】 陈仁；

【导师】 胡义华；

【作者基本信息】 广东工业大学 ， 物理电子学， 2008， 硕士

【摘要】 SrAl₂O₄：Eu²⁺，Dy³⁺是上个世纪九十年代发展起来的新型长余辉材料，其发光亮度、余辉时间以及化学稳定性均优于传统长余辉材料，因而得到广泛的应用。但是此发光材料发光颜色单一，发射光谱主要集中在440～520nm范围，而且发光的亮度不够强，仅仅能够应用在弱光照明的领域。掺杂是改善发光材料性能的一个重要途径，同时稀土元素的原子具有未充满的受到外界屏蔽的4f⁶5d电子组态，具有丰富的电子能级和长寿命激发态，能级跃迁通道多达20余万个，可以产生多种多样的辐射吸收和发射。因此本研究尝试采用稀土元素对SrAl₂O₄：Eu²⁺，Dy³⁺进行掺杂，希望提高材料的发光特性。本文采用燃烧合成方法，在600℃温度条件下，首次分别合成钬、镱、钕稀土元素掺杂的SrAl₂O₄：Eu²⁺，Dy³⁺长余辉发光材料，同时研究了掺杂对此材料发光性能的影响。通过X射线衍射和发射光谱分析，结果表明微量的稀土元素的掺杂几乎没有改变材料的晶体结构以及Eu²⁺发光中心电子的4f⁶5d→4f⁷的跃迁环境。余辉衰减特性曲线显示，与SrAl₂O₄：Eu²⁺，Dy³⁺相比较，SrAl₂O₄：Eu²⁺，Dy³⁺，Yb³⁺和SrAl₂O₄：Eu²⁺，Dy³⁺，Ho³⁺的发光亮度有明显提高，而SrAl₂O₄：Eu²⁺，Dy³⁺，Nd³⁺的发光亮度却显著的降低。通过软件拟合分析显示，钬、镱或钕稀土元素掺杂并不能提高SrAl₂O₄：Eu²⁺，Dy³⁺长余辉发光材料的余辉衰减时间。对热释光谱分析和研究发现，不同的发光体存在不同深度的陷阱能级，而且陷阱能级的深度与余辉时间相对应。本文通过对稀土元素掺杂SrAl₂O₄：Eu²⁺，Dy³⁺的研究，发现一定量和合适的稀土元素掺杂可以大大提高材料的发光性能，这对扩大长余辉发光材料的应用领域起到很大作用。更多还原

【Abstract】 SrAl₂O₄:Eu²⁺, Dy³⁺ phosphor is a new type of long lasting phosphorescent material, which is discovered in 1990’. Compared with traditional sulfide phosphors, this phosphor possesses safer, chemically stable, and very bright and long-lasting phosphorescence, which leads to a large filed of applications。However, the luminescent intensity of the phosphorescent material is very low and the color is not rich, therefore, it is very necessary to further improve the luminescent properties to realize more advanced and practical applications. As is known that lanthanon doping is a good method to improve the luminescent properties of the material and it is our original intention as well.The modification on long afterglow properties of SrAl₂O₄ Eu²⁺, Dy³⁺ phosphor by Holmium、Ytterbium or Neodymium doping were studied for the first time. The phosphors were synthesized by the combustion method at the temperature of 600℃. X-ray diffraction patterns and emission spectra indicate that the Holmium、Ytterbium or Neodymium doping almost does not make any change of the crystal structure and the Eu²⁺ transition environment between 4f⁶5d and 4f⁷.The decay curves demonstrate that luminescent intensity can be enhanced by Holmium and Ytterbium doping, but the decay time of the phosphors do not have any improvement. Further research of thermally stimulated luminescence discovers that different trap levels exist in different phosphors and the depth of the trap levels are well corresponded with decay time of the phosphors.Finally, it can be drawn a concludsion that the phosphors doped with appropriate amount of Holmium and Ytterbium result in very intense and bright phosphorescent emission, which can be used in more extensive application field.更多还原