B掺杂SrTiO_3电子结构的第一性原理计算  

First-principles calculations on electronic structures of B-doped SrTiO_3

作　　者：刘晨吉[1,2] 贾云龙[1,2] 刘红[1,2] 吴一[1,2] 刘磊[1,2] 郑树凯[1,2,3] 

机构地区：[1]河北大学电子信息工程学院,保定071002 [2]河北大学计算材料与器件模拟研究中心,保定071002 [3]河北省数字医疗工程重点实验室,保定071002

出　　处：《中国有色金属学报》2016年第3期616-622,共7页The Chinese Journal of Nonferrous Metals

基　　金：国家留学基金资助项目([2014]-3012)~~

摘　　要：利用基于密度泛函理论(DFT)的第一性原理平面波超软赝势法,对未掺杂、B替位Sr、B替位Ti、B替位O和B间隙掺杂SrTiO_3的晶格参数、Mulliken电荷布居、能带结构、态密度和光吸收系数进行计算。结果表明:B替位Sr和B替位Ti掺杂对SrTiO_3电子结构和光学性质的影响不显著;B替位O掺杂则在SrTiO_3的禁带中引入3条杂质能级,杂质能级上的电子可以吸收能量较小的光子跃迁至导带,光吸收强度从可见光长波段550nm开始逐渐增加,光谱吸收边红移;B以间隙原子的形式掺杂时,SrTiO_3的禁带宽度大幅增大,电子跃迁能增加,光谱吸收边蓝移。The lattice parameters, Mulliken charge populations, energy band structures, density of states and absorption coefficients of pure SrTiO3, B substitutes for Sr or Ti, and interstitial B doped SrTiO3 were studied by the first-principles plane wave ultra-soft pseudo-potential method based on the density functional theory (DFT). The results show that the impacts on the electronic structures and optical properties of SrTiO3 are not significant when the B atom substitutes for the Sr or Ti atom. When B substitutes for O atom, three impurity levels are introduced into the band gap of SrTiO3, the electrons on the impurity levels can transit to the conduction band by absorbing photon of less energy, the intensity of light absorption begins to increase gradually from visible light wavelength of 550 nm and the spectral absorption edge has a red shift. When B is in the form of interstitial, the width of forbidden band of SrTiO3 enlarges significantly and the transition energy of the electrons increases, which results in the blue shift of the spectral absorption edge.

关 键 词：SRTIO3 B掺杂 第一性原理 电子结构 

分 类 号：O643.36[理学—物理化学] O641.1[理学—化学]