BaTaO_2N局域电子结构及光学性质的第一原理计算

First-principles calculation for local electronic structure and optical properties of BaTaO_2N

采用基于密度泛函理论的第一原理方法计算了BaTaO2N的局域能带结构、态密度和光学性质.能带结构结果表明,BaTaO2N属于直接带隙半导体,其能带宽度Eg=0.62 eV;价带主要由O 2p,N 2p和Ta 5d态电子构成,且N 2p态位于价带顶;导带主要由Ta 5d态电子构成.基于能带结构和态密度分析了BaTaO2N的介电函数以及折射率、光电导率、吸收谱和能量损失函数等光学性质.静态介电常数1(0)=6.13,折射率n0=2.48,在紫外区有较大的吸收系数.

The local band structure, density of states and optical properties of BaTaO2N have been calculated using the first-principle density functional theory. The results of band structure indicate that BaTaO2N is a semiconductor with a direct bandgap of 0.62 eV, the valence band is mainly composed of the density of states of O 2p, N 2p and Ta 5d electrons with N 2p located at the top, while the conduction band is mainly composed of the density of states of Ta 5d electrons. The optical properties of BaTaOEN such as dielectric function, refractivity, photoconductivity, absorption spectrum and energy loss function have been analyzed based on energy band and density of states. The static dielectric constant （0） is estimated to be 6.13 and the reflectivity no is estimated to be 2.48.