AZO(ZnO:A1)电子结构与光学性质的第一性原理计算

计算了不同Al掺杂浓度下ZnO体系电子结构和光学属性.分析了掺杂对AZO(ZnO:A1)晶体结构、能带、态密度、光学性质的影响.所有计算都是基于密度泛函理论框架下的第一原理平面波赝势方法.计算结果表明:Al掺杂ZnO在导带底引入了大量由掺杂原子贡献的导电载流子,明显提高了体系的电导率.费米能级进入导带.同时,光学性质的计算表明光学带隙明显展宽,且向低能方向漂移;AZO透明导电材料的光学透过率在可见光范围内高达85%,紫外吸收限随着掺杂浓度的增加而发生蓝移.所有计算表明AzO材料可作为优良的透明导电薄膜材料.     

PbxSr1-xTiO3的电子结构

在广义梯度近似下, 采用基于密度泛函理论框架下的超软赝势平面波和虚拟晶体近似方法, 计算了不同Pb/Sr摩尔比的PbxSr1-xTiO3(PST)固溶体的精细结构, 确定了A位离子在铁电相的平衡构型. 利用虚拟晶体近似方法分别计算了摩尔比x为0.6、0.7的PbxSr1-xTiO3精细结构. 结果表明, 在钛酸锶铅固溶体中, 随着Pb的摩尔比增大, 晶胞体积膨胀, c/a值增大. 当0.6相似文献   

First Principles Study of Adsorption and Reaction of CO on SrTiO3 （100） Surface： the Role of Surface Oxygen Vacancies

The adsorption and reaction of CO on SrTiO3 （100） surface with and without surface oxygen vacancy are investigated by the first-principles calculation based on the density functional theory. The calculated results reveal that the oxygen vacancy site prefers to the activation of the C-O bond. The adsorption energies increase to 1.0855 and 0.3245eV for defect-CO and defect-OC orientations, respectively. Particularly the C-O bond is elongated by about 0.1285 ？ in the defect-OC orientation compared with that in the Ti-OC one without surface oxygen vacancies. There is predominantly a chemisorption mechanism between the CO molecule and the surface in the defect-CO orientation.     

从玻恩的教学方式看量子力学的诞生

玻恩作为哥廷根学派的领袖,在20世纪物理学界取得了丰硕的成果.玻恩还是一位出色的物理学教授,他培养出了许多伟大的物理学家以及数学家、生物学家.量子力学诞生在20世纪的德国,和玻恩投入大量精力以比较独特的方式培养学生以及带领他们在物理学前沿积极探索的教学工作是紧密相关的.通过这种分析,也能凸显出我们中国物理学界尤其物理教育界存在的一些现实问题.     

PbxSr1-xTiO3的电子结构

在广义梯度近似下,采用基于密度泛函理论框架下的超软赝势平面波和虚拟晶体近似方法,计算了不同Pb/Sr摩尔比的PbxSr1-xTi03(PST)固溶体的精细结构,确定了A位离子在铁电相的平衡构型.利用虚拟晶体近似方法分别计算了摩尔比x为0.6、0.7的Pb1-xSr1-xTiO3精细结构.结果表明,在钛酸锶铅固溶体中,随着Pb的摩尔比增大,晶胞体积膨胀,c/a 值增大.当0.6相似文献   

Effect of In-Doping on Electronic Structure and Optical Properties of Sr2TiO4

The effect of In doping on the electronic structure and optical properties of Sr2 TiO4 is investigated by a firstprinciples calculation of plane wave ultrasoft pseudopotentials based on density functional theory. The calculated results reveal that corner-shared TiO6 octahedra dominate the main electronic properties of Sr2TiO4 and the covalency of the Ti-O（1） bond in the ab plane is stronger than that of the Ti-O（2） bond along the c-axis. After In doping, there is a little lattice expansion in Sr2In0.125 Ti0.875 O4 and the interaction between the Ti-O bond near the impurity In atom is weakened. The binding energies of Sr2TiO4 and Sr2In0.125Ti0.875O4 estimated from the electronic structure calculations indicate that the crystal structure of Sr2In0.125 Ti0.875 O4 is still stable after doping, but its stability is lower than that of undoped Sr2TiO4. Moreover, the valence bands （VBs） of the Sr2In0.125Ti0.875O4 system consist of O 2p and In 4d states, and the mixing of O 2p and In 4d states makes the top VBs shift significantly to high energies, resulting in visible light absorption. The adsorption of visible light is of practical importance for the application of St2 TiO4 as a photocatalyst.