Sb掺杂闪锌矿GaAs电子结构和光学性质第一性原理研究

The First Principles Study on Electronic and Optical Properties of Sb-doped Zinc Blende GaAs

采用基于密度泛函理论(DFT)框架下广义梯度近似平面波超软赝势法,计算了不同浓度Sb掺杂闪锌矿GaAs体系GaAs1-xSbx(x=0,0.25,0.5,0.75,1)的电子结构和光学性质,包括能带、态密度、复介电函数和吸收系数。计算结果表明,Sb掺杂导致体系晶格常数线性增大,并使得体系导带和价带组成发生改变,禁带宽度呈二次多项式变化。随着掺杂浓度的增加,体系静态介电常数线性增大,吸收带边出现了明显的红移现象。分析了掺杂Sb诱发GaAs1-xSbx体系的电子和光学性质改变,为Sb掺杂闪锌矿GaAs在光电子学和微电子学方面的实际应用提供了一定的理论依据。

Electronic structure and optical properties of GaAs1-x Sbx （x=0, 0. 25, 0. 5, 0. 75, 1） were investi- gated by using the plane waves uhrasoft pseudopotential technique based on the density functional theory （DFT）. The band structure, density of states, complex dielectric function and absorption coefficient were obtained. The calculated results indicate that Sb doping leads to linearly increasing lattice constants and changs the components of valence and conduction bands of GaAs. The band gap of doped system appears a quadratic polynomial variation tendency, which results in the variations of the optical properties of the system. With the increase of the Sb content, the static dielec- tric constant ε1 （0） increases linearly and the absorption wavelength appears an obvious red-shift. These offer a theo- retical basis for the application of Sb-doped GaAs in photoelectronics and microelectronics.