Sr_2CeO_4的发光性能及理论计算研究  

Photoluminescence properties and theoretical calculations study of Sr_2CeO_4

作　　者：肖宁[1] 胡太平[1] 徐源[1] 

机构地区：[1]重庆邮电大学理学院,重庆400065

出　　处：《重庆邮电大学学报（自然科学版）》2016年第6期831-835,共5页Journal of Chongqing University of Posts and Telecommunications(Natural Science Edition)

基　　金：国家自然科学基金(11404047);重庆市自然科学基金(CSTC 2012JJA90019)~~

摘　　要：采用高温固相法制备Sr_2CeO_4样品,并对样品进行X射线衍射(X-ray diffraction,XRD)、紫外可见(UV-visible,UV-Vis)反射率光谱分析及光致荧光光谱(photoluminescence spectra,PL)分析。用第一性原理的密度泛函理论对Sr_2CeO_4的结构、电荷密度分布建模,对Sr_2CeO_4的电荷迁移态跃迁机制以及宽的吸收峰与发射峰的成因进行理论分析。实验结果表明,制得的样品为正交晶系的可能性较大;Sr_2CeO_4的激发和发射均为宽带,激发峰形状不对称,可能存在双激发源;发射光谱是位于472 nm附近的宽峰,呈强的蓝白光。样品的第一性原理建模研究结果表明,Sr_2CeO_4中存在2种O-Ce与2种O-Sr,这与Sr_2CeO_4的双峰激发有密切关系;Sr_2CeO_4的发光机理源于电荷迁移态跃迁发光。The Sr2CeO4samples were synthesized by high temperature solid state reaction. The crystal structure and the optical properties of the sample were characterized. Meanwhile,the structure and charge density distribution of the Sr2CeO4were analyzed by theoretical study of first principles. The charge transfer（ CT） transition mechanism and the reason of the wide excitation and emission bands of the sample were studied by the same methods as well. The results reveal that the obtained sample is orthogonal. And there might be two excitation sources because of the asymmetric broad excitation band.The emission of the sample centered at 472 nm,being a strong white blue light. The study of first principle method shows that two kinds of O-Ce and O-Sr exist in the Sr2CeO4crystal,which is related to the asymmetric excitation band. The luminescence mechanism of Sr2CeO4is the charge transfer state transition.

关 键 词：SR2CEO4 高温固相法 发光特性 第一性原理 

分 类 号：TN204[电子电信—物理电子学] O433.4[机械工程—光学工程]