中文摘要：

采用基于密度泛函理论（ DFT）的第一性原理平面波超软赝势方法,计算并分析纤锌矿ZnO和Al2 O3的电子结构（能带结构和态密度）和光学性质（介电常数、光电导率、能量损耗和光吸收）。计算结果表明：ZnO为直接带隙半导体,Al2 O3为间接带隙半导体。 ZnO和Al2 O3介电常数虚部分别在10.21 eV和10.7 eV附近出现了明显的介电峰。 ZnO的介电峰值比Al2 O3的大。 ZnO的复光电导率在10~13 eV出现两个峰,Al2 O3的复光电导率仅在10 eV附近出现了1个明显的吸收峰。 ZnO的能量损失比Al2 O3的小。 ZnO在紫外区的光吸收比较强,在可见光范围比较弱,Al2 O3的光吸收在紫外区,当波长大于250 nm时基本没有光吸收。研究结果可为开发新的非线性光学材料提供理论依据。

英文摘要：

The electronic structure （ energy band and density of states） and optical properties （ die-lectric function, conductivity, loss function, optical absorption） of ZnO and Al2 O3 were calculated by the first-principle pseudo potential method based on the density functional theory （ DFT ）.The results show that ZnO is a direct gap semiconductor, while Al2 O3 is an indirect-gap semiconduc-tor.The imaginary part of dielectric constant for ZnO and Al2 O3 appear obvious peak at about 10.21 eV and 10.7 eV, respectively.The dielectric constant of ZnO is larger than that of Al2 O3 . There are two peaks of conductivity at the energy of 10~13 eV for ZnO, while only one peak of con-ductivity appears about 10 eV for Al2 O3.Energy loss of ZnO is smaller than that of Al2 O3.ZnO has stronger absorption in the UV-region, but has weaker absorption in the visible light spectrum.Optical absorption of Al2 O3 is located in the UV region, and there is no absorption beyond the wavelength of 250 nm.The study provides the theoretical foundation for developing new nonlinear optical materials.