中文摘要：

目前,Pr掺杂对锐钛矿TiO2带隙和吸收光谱研究结果存在相反的结论,红移和蓝移两种实验结果都有文献报道.为解决这个矛盾,本文基于密度泛函理论框架下的第一性原理平面波超软赝势方法,对纯的和不同浓度Pr高掺杂锐钛矿TiO2的电子结构和吸收光谱进行了计算.计算结果表明,与纯锐钛矿TiO2相比较,Pr掺杂后,掺杂量越增加,掺杂体系各原子电荷量越减小,掺杂体系总能量越高,形成能越大,稳定性越下降,带隙越窄,吸收光谱红移现象越显著,吸收强度越强.计算结果与实验结果相一致.

英文摘要：

Nowadays, the studies on band gap and absorption spectrum of TiO2doped with Pr lead to opposite conclusions.Two experimental results about red-shift and blue-shift are reported in the literature. We have set up models for pure TiO2and difierent doping concentrations of Pr-doped TiO2to calculate the electronic structure and absorption spectrum based on the first-principle plane-wave ultrasoft pseudopotential in terms of the density functional theory（DFT） to slove the above problem. Results indicate that under the condition of heavy doping Pr, compared with the pure TiO2, as the Pr concentration increases the atomic charge of the doped system reduces and the total energy of the doped system becomes higher, and its formation energy will be greater. This makes the stability decline, the band gap narrowed,the absorption spectrum red-shift, and the absorption strength more significant. The results of the calculation is in agreement with the experimental data.