利用漫反射光谱研究SrAl_2O_4长余辉材料中Dy^(3+)和Eu^(2+)相关陷阱能级  

Investigation on Trap levels in Dy^(3+) and Eu^(2+) Doped SrAl_2O_4 Long Persistent Luminescent Material by Diffuse Reflectance

作　　者：傅佳意 毛启楠[1] 沈东东 席俊华[1] 季振国[1] FU Jiayi;MAO Qinan;SHEN Dongdong;XI Junhua;JI Zhenguo(College of Materials & Environmental Engineering,Hangzhou Dianzi University,Hangzhou 310018,China)

机构地区：[1]杭州电子科技大学材料与环境工程学院,浙江杭州310018

出　　处：《材料科学与工程学报》2018年第6期898-903,共6页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(61372025)

摘　　要：在长余辉发光物理机制的研究中,确定发光材料中的缺陷能级是非常重要的。本文通过高温固相法制备了两组SrAl_2O_4∶Dy^(3+)和SrAl_2O_4∶Eu^(2+)样品,并采用漫反射光谱测定了SrAl_2O_4中一系列与Dy^(3+)和Eu^(2+)相关的吸收峰。对于SrAl_2O_4∶Dy^(3+)和SrAl_2O_4∶Eu^(2+),在其吸收谱的较低能量(长波长)和较高能量(短波长)区域内分别存在一组吸收峰。通过这些吸收峰可确定Dy^(3+)和Eu^(2+)掺杂在SrAl_2O_4带隙中引入的陷阱深度。结果表明Dy^(3+)离子能够在SrAl_2O_4中形成浅能级和深能级陷阱,而Eu^(2+)离子仅会形成浅能级陷阱。与文献报道的陷阱相比较,这些陷阱大部分和其它方法测得的数据相一致,小部分则是首次报道,可能是其它方法的测试范围所限而无法测得。我们认为距离导带0.6至1.2eV范围内的Dy^(3+)相关陷阱在SrAl_2O_4∶(Eu^(2+),Dy^(3+))长余辉发光过程中起着关键的作用。Trap levels in persistent luminescent materials are of great importance to clarify the persistent luminescence process.In order to study the trap levels in SrAl2O4,two groups of SrAl2O4:Dy3+and SrAl2O4: Eu2+samples were prepared by conventional solid-state reaction.Dy^3+and Eu^2+relevant absorption peaks in SrAl2O4 were determined by diffuse reflectance spectra.A lower (in the longer wavelength region)and a higher (in the shorter wavelength region)energy absorption bands were found for both Dy^3+-doped and Eu^2+-doped SrAl2O4.Dy^3+and Eu^2+-related trap levels in the bandgap of SrAl2O4 were obtained by the absorption bands. The result shows that shallow and deep traps are introduced by Dy^3+doping in SrAl2O4,while only shallow traps are introduced by Eu^2+doping.Compared with the traps reported in other literatures,most of the traps in this paper are in good agreement with the data obtained by other methods,and a few traps has not been reported by other methods due to the measurement limitations.In our opinion,Dy^3+related traps located from 0.6 to 1.2eV below the conduction band is considered to play a crucial role in the long persistent luminescence of SrAl2O4(Eu^2+,Dy^3+).

关 键 词：铝酸锶 陷阱能级 漫反射光谱 

分 类 号：TB34[一般工业技术—材料科学与工程]