稀土元素铽镧掺杂对硫氧化钆晶格场的影响及发光性能研究  

Influence of Rare Earth Terbium and Lanthanum Doping on the Lattice Field and Luminescence Performance of Gadolinium Oxysulfide

作　　者：张静[1,2] 许乃岑[1] 沈加林[1] 金凡[1] ZHANG Jing;XU Naicen;SHEN Jialin;JIN Fan(Nanjing Center,China Geological Survey,Nanjing 210016,China;Nanjing Tech University,Nanjing 211816,China)

机构地区：[1]中国地质调查局南京地质调查中心,江苏南京210016 [2]南京工业大学,江苏南京211816

出　　处：《岩矿测试》2025年第2期254-267,共14页Rock and Mineral Analysis

基　　金：中国地质调查局地质调查项目“苏皖沿江凹陷带油气页岩气调查评价”(DD20221662);中国自然科学基金联合基金重点支持项目“浙闽火山岩区蚀变岩帽叶腊石和明矾石矿物指针研究”(U234420091);中国地质调查局南京地质调查中心成果转化项目“月球及火星模拟样品矿物组成研究”(NJZXK2023-034)。

摘　　要：稀土硫氧化物具有较好的传能效率、热稳定性和化学稳定性,其作为发光材料的基质被广泛应用于防伪、显示器、发光二极管、医学影像等领域。由于硫氧化钆(Gd_(2)O_(2)S)的晶体空间结构较宽,当间隙离子进入其中,或阳离子、阴离子形成空位时,晶体结构也依然保持不变。但硫氧化钆荧光粉容易发生团聚现象,使得样品颗粒尺寸较大,降低了样品颗粒的堆积密度,提高了能量的散射率,导致获得的光不均匀。用于显示设备时,粉末粒径大会导致在同一视域里像素数量较少,分辨率较差。本文以Gd_(2)O_(2)S为研究对象,采用硫熔法制备了硫氧化钆荧光粉,引入稀土离子Tb^(3+)、La^(3+)作为掺杂离子,通过优化稀土离子的掺杂量,获得结晶度高、分散性好、尺寸均匀性相对较好的Gd_(2)O_(2)S基荧光粉。利用荧光分光光度计、X射线衍射(XRD)等测试技术,探讨稀土掺杂对Gd_(2)O_(2)S晶格场的影响及发光性能的影响。XRD结果表明:①荧光粉为纯六方晶体结构;②Tb^(3+)、La^(3+)替代Gd^(3+)进入Gd_(2)O_(2)S的晶格位置。荧光粉的荧光光谱图显示:①掺入Tb^(3+)后,在544nm处会发生^(5)D_(4)→^(7)F_(5)的浓度猝灭,是由于电偶极-电偶极跃迁引起的;②发光强度在Tb^(3+)掺杂浓度为2mol%时最大;③La^(3+)的掺杂增强了硫层的电负性,所以随着掺杂量的增加,晶胞之间的排斥力也逐渐增强,晶粒尺寸逐渐减小,发光强度也随之增强;④当La^(3+)掺杂浓度为60mol%时,发光强度为未掺杂La^(3+)样品的1.9倍。本文通过计算电多级级数分析离子间能量转移的过程,从而确定了发光材料Tb^(3+)、La^(3+)的最佳掺杂浓度。Rare earth oxysulfides possess excellent energy transfer efficiency,along with remarkable thermal and chemical stabilities.Currently,it remains a challenging research focus to fluorescent powder characterized by a small particle size,narrow distribution,and high luminescence intensity.Here,we primarily investigate ways to enhance the luminescent intensity of rare earth sulfur oxide phosphors synthesized via the sulfur fusion method and to reduce the particle size of these phosphors.By using the sulfur melting technique,fluorescent powder was created,with doping ions Tb^(3+)and La^(3+)of rare earth integrated.Various methods such as fluorescence spectroscopy,and X-ray diffraction were employed to investigate how rare earth terbium and lanthanum doping impacts the lattice structure and luminescent capabilities of gadolinium oxysulfide.The experimental results indicate that the fluorescent powder has a pure hexagonal crystal structure.The luminescence intensity of the fluorescent powder reaches its maximum when the doping concentration of Tb^(3+)is 2mol%.When the La^(3+)doping concentration is 60mol%,the luminescence intensity is 1.9 times that of the undoped La^(3+)sample.Therefore,introducing rare earth terbium and lanthanum atoms can effectively improve the optical properties of fluorescent powders.

关 键 词：发光 稀土离子掺杂 硫氧化钆 荧光分光光度计法 X射线衍射法 

分 类 号：P575[天文地球—矿物学]