Rb_2Te W_3O_(12)电子结构及光学性质的第一性原理研究

Ab inition studies on the electric and optical properties of Rb_2TeW_3O_(12)

采用平面波超软赝势法对Rb2 TeW3O1 2 基态的几何结构、能带结构和光学特性等进行了系统的研究 .几何结构研究不仅对基态平衡时的几何参量进行了优化计算 ,还对内部坐标做了优化 ,其结果和实验测量值符合得很好 .电子结构的研究表明 ,Rb2 TeW3O1 2 属于宽禁带直接带隙半导体 ,禁带宽度为 2 2 3eV ,W 5d和O 2p轨道之间强烈杂化形成W—O共价键 .计算了光学性质 ,给出了Rb2 TeW3O1 2 的介电函数实部ε1 、虚部ε2 及相关光学参量 ,理论计算的静态介电常数为 5 2

By using the plane-wave ultrasoft pseudopotential method, the geometric parameters, electric and optical properties of Rb2TeW3O12 are investigated. The equilibrium lattice constants are in good agreement with experimental data. The electric structures reveal that Rb2TeW3O12 is a direct wide-band semiconductor and the band gap is 2.23eV; W 5d and O 2p states form a strong W-O covalent bond. Optical properties have been studied and we have presented the dielectronic functions epsilon(1) and epsilon(2) Static dielectric constant epsilon(0) = 5.29 have been gained.