高压下BaHfO_3电子结构与光学性质的第一性原理研究  

First-principles study on the electronic structures and optical properties of BaHfO_3 under high pressure

作　　者：顾芳[1] 王俊锋[1] 陈云云[1] 刘清惓[2] 张加宏[2] 

机构地区：[1]南京信息工程大学物理与光电工程学院,南京210044 [2]南京信息工程大学江苏省气象探测与信息处理重点实验室,南京210044

出　　处：《原子与分子物理学报》2012年第5期933-940,共8页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(41075026)

摘　　要：从第一性原理出发,在局域密度近似下,采用基于密度泛函理论的平面波超软赝势计算方法系统地研究了高压对BaHfO_3电子结构与光学性质的影响.能带结构分析表明;无压强和施加正压强作用时,BaHfO_3为直接带隙绝缘体,而施加负压强时,BaHfO_3则转变为间接带隙半导体;BaHfO_3的带隙随压强增加而减小,且具有明显的非线性关系.对光学性质的分析发现:施加正压强后,光学吸收带边产生蓝移;负压强作用时介电函数虚部尖峰减少,光学吸收带边产生红移;施加压强后BaHfO_3的静态介电常数和静态折射率均增大.上述研究表明施加高压有效调制了BaHfO_3的电子结构和光学性质,计算结果为BaHfO_3光电材料的设计与应用提供了理论依据.The cubic perovskite-type BaHfO3 has been investigated by the first-principles plane-wave pseudo-potential method based on the density function theory. The electronic structure and optical properties of BaHfO3 are calculated under high pressure. The band structure analysis indicates that BaHfO3 is a direct-band-gap insulator in the case of without pressure and imposing positive pressure, while BaHfO3 is transformed into an indirect-band-gap semiconductor under negative pressure. Besides, the band gap of BaHfO3 decreases with an increase of pressure, and it appears obvious nonlinear relationship. The optical properties calculations show that the absorption edge is blue-shifted when imposing positive pressure, while the absorption edge is red-shifted and peaks of imaginary part of the dielectric function are decreased when imposing negative pressure. Furthermore, the static dielectric constant and static refractive index of BaHfO3 under high pressure are increased. In a word, the involved results have shown that the high pressure effectively modulates the electronic structure and optical properties of BaHfO3, which will provide a theoretical basis for the design and application of BaHfO3 optoelectronic materials.

关 键 词：BaHfO3 第一性原理 压强 电子结构 光学性质 

分 类 号：O472[理学—半导体物理]