Sm掺杂对锐钛矿TiO_2电子寿命和红移影响的第一原理研究

First-principles study of the electronic life and red shift effect of Sm-doped anatase TiO_2

基于密度泛函理论平面波超软赝势方法,采用第一性原理对不同浓度Sm掺杂锐钛矿相TiO2超胞的结构优化、形成能、能带结构、态密度、差分电荷分布和光学性质进行了计算。结果表明Sm掺杂后锐钛矿相TiO2超胞的电子结构变化很大。在限定的浓度范围内,掺杂浓度越小,形成能越小,掺杂越容易,电子寿命越长,带隙宽度越窄,吸收光谱红移越显著。计算结果与实验结果一致。

Based on first principles within density-functional theory, using the plane-wave ultra-soft pseudo po tential method, We have calculated the geometry optimization, the formation energy, the band structure, the density of states, the electron density differences, and the with different Sm concentrations. The results show that, optical properties of Sm-doping anatase TiO2 models when Sm atom was doped in TiO2, it significantly changes the electron structure of the anatase TiO2 supercell. Within the concentration range set in this work, with the decrease of doping concentration, the formation energy of the Sm system becomes lower, the doped becomes easier, the electronic has a longer life, the doping of Sm atom also leads to the decrease of band gap, and more significant red shift of the absorption spectrum. The calculation results are in agreement of the experi ment results.