节点文献
稀土掺杂四硼酸钇铝荧光粉的制备与性能研究
Synthesis and Properties of Rare Earth Ions Doped Yttrium Aluminium Both Borate Phosphors
【作者】 张红国;
【导师】 曹全喜;
【作者基本信息】 西安电子科技大学 , 材料学, 2009, 硕士
【摘要】 四硼酸铝钇(YAl3(BO3)4, YAB)以其优异的力学、热学和光学性能,而在发光材料和激光材料领域具有广阔的应用前景。本论文对稀土离子掺杂的YAB红光及绿光荧光粉进行了研究,讨论了粉体合成、制备工艺、结构与性能之间的关系,取得的结果如下:1、分别采用固相合成法、硝酸盐热分解法和溶胶-凝胶燃烧法制备了YAB粉体。通过X射线衍射(XRD)和扫描电镜(SEM)分析了所得粉体的物相和形貌。结果表明:三种方法合成YAB纯相的最低温度依次为:1200℃、1100℃和1000℃,且制备过程中硼酸的最佳用量分别为140%、120%和120%。另外,对溶胶-凝胶燃烧法中硝酸盐和柠檬酸的比值对合成粉体的影响进行了研究。SEM分析显示,当为二者比值为1:1.5时合成的YAB粉体粒度均匀,且粉体具有较好的分散性。2、采用上述三种方法分别合成了(Y,Gd)Al3(BO3)4:Eu3+荧光粉,研究了合成方法,稀土离子的性质和浓度等因素对其粉体发光性能的影响。结果表明:溶胶-凝胶燃烧法、硝酸盐热分解法和固相合成法所合成的荧光粉发光强度依次降低;对于溶胶-凝胶燃烧法所制备的(Y,Gd)Al3(BO3)4:Eu3+荧光粉,Eu3+的最佳掺杂浓度为18%;且随着Gd3+浓度的增加,Eu3+的发射强度先增大而后减小,当掺杂浓度为75%时强度最大。3、采用溶胶-凝胶燃烧法在1100℃下合成了纯相(YGd)Al3(BO3)4:Tb3+粉体,研究了Tb3+和Gd3+掺杂量对荧光粉性能的影响。结果表明:随着Tb3+浓度的增大,所合成粉体的发光强度先增大后减小,Tb3+的猝灭浓度为25%;在Tb3+浓度确定时,其发射强度随着Gd3+掺杂量的增大而增大。
【Abstract】 Yttrium aluminium both borate (YAl3(BO3)4, YAB) have good properties of mechanics, thermotics and optics, which have a wide applications in the matrix materials of luminescent powder and laser. In this paper, rare earth ions doped YAB phosphors were investigated. Results are obtained as follows:1 YAB powders were synthesized by solid state reaction, pyrogenic decomposition of nitrate, sol-gel combustion methods, respectively. Results of X-ray powder diffractometry (XRD) and scanning electron microscopy (SEM) show that:For these three methods, the lowest temperatures at which the single phase powders were synthesized were 1200℃, 1100℃and 1000℃, respectively.And in order to obtain the single phase of YAB, 40%,20% and 20% of excess H3BO3 were used in the three methods, respectively. SEM shows that the powder synthesized by sol-gel combustion method has the particles with the size of about 400nm and good dispersivity when the molar ratio of nitrate to citric acid is 1: 1.5.2 (Y,Gd)Al3(BO3)4:Eu3+ phosphors were synthesized by those three methods respectively. The XRD and SEM result show that the powder synthesized by sol-gel combustion has good dispersivity and need low temperature. The effects of doping with Gd3+ ion were studied.It is found that the emission intensity of Eu3+ increases firstly, and then decreases under the excitation of UV with the increasing Gd3+ concentration. An optimum Gd3+doping concentration of 75% is obtained.3 The powders of (Y,Gd)Al3(BO3)4:Tb3+ were synthesized by sol-gel combustion method at 1000℃. It is found that the quenching concentration of Tb is about 25%. Emission spectra show that the luminescence intensity of Tb3+ increases with the increasing Gd3+ doping concentration due to the fact that there exists the energy transfer of Gd3+→Tb3+ (6P7/2→5DJ) in (YGd)Al3(BO3)4:Tb3+.