金红石相VO_2电子结构与光电性质的第一性原理研究

First principles study of the electronic structure and photoelectric properties of rutile vanadium dioxcide

采用完全势线性缀加平面波方法(FP-LAPW)结合密度泛函+U(DFT+U)模型计算了金红石相VO2的电子结构和光学性质.电子态密度计算结果表明所采用的方法可以较好的描述体系的导带电子结构.计算得到体系为导体,V—O键主要由O原子的2p轨道与V原子的3d轨道杂化形成,外加光场垂直和平行于c轴时体系的等离子振荡频率为3.44eV和2.74eV,光电导率在0—1eV之间有一个与带内跃迁有关的德鲁德峰,而大于1eV的光电导率主要由电子带间跃迁产生,得到并分析了带内跃迁过程和带间跃迁过程各自对反射谱和电子能量损失谱的贡献.

The electronic structure and the photoelectric properties of rutile based VO2 are investigated using the FP-LAPW method which is combined with the DFT＋U method.The calculated density of statas（DOS） shows that the DFT＋U method can describe the conductive band properly.The V-O bonding in VO2 is induced mainly through the strong hybridization of V3d orbital and O2p orbital.The calculated plasma frequency is 3.44 eV when the applied light field is perpendicular to the c axis and 2.74 eV when the applied light field is along the c axis.The optical conductivity spectrum shows a Drude-like peak is between 0 eV and 1 eV while in upper area the interband contribution is more important.Finally,the reflection spectrum and the election energy loss spectrum（EELS） are calculated and analyzed.