【摘要】 采用内部求和d轨道处理下的线性丸盒轨道方法,对在GaAs衬底上生长的应变层越晶格（InAs）_n/（GaAs）_n（001）,（n=1,2,3,4,5）的电子结构进行了第一性原理计算,得出了其能带结构、带隙值和态密度分布.本文得出的（lnAs）₁（GaAs）₁在布里渊区中各高对称点的能隙值与从头赝势方法的计算结果相一致,得出的带隙值与光致发光实验结果符合得很好.为了确定该系统的价带能量不连续值(△E_?),并全面考虑各因素对其的影响,本文提出一种基于自治超原胞计算及其冻结势处理下的形变势方法.该方法全面考虑了界面电荷转移（及其引起的偶极子势）和弹性应变以及自旋-轨道相互作用三方面的因素对△E_?,值的影响.本文得出的InAs/GaAs系统的△E_?值为—0.201eV,与X射线光电子能谱的测量值—0.17±0.07eV相一致.更多还原

【Abstract】 This paper reports an ab initio study on electronic structures of strained-layer superlattices (SLS’s) (InAs)n/(GaAs)n(001), (n= 1,2,3,4,5) grown epitaxially on a GaAs-substrate, by mea ns of the linearized-muffin-tin-orbitals band structure method in an internal summation treatment for d orbitals. Present results of the energy gap values at high symmetry points in Brillouin zone for (InAs)l(GaAs)1 are consistent with those obtained by ab initio pseudopotential calculations. The band gaps given by this work are in good agreement with the experimental data of photolu-minescence spectra. In order to determine the valence band discontinuity at these SLS’s, we suggest a theoretical method which adopts deformation potential theory to treat the effects of elastic strain and spin-orbit splitting on the basis of selfcon-sistent supercell calculations and a frozen-potential approach. The effects of interface charge transfer, elastic strain and spin-orbit splitting on the valence band discontinuity are all taken into account in our approach. The determined result is 0.201eV, in good agreement with the experimental datum of X-ray photoemission spectroscopy: 0.17 + 0.07eV.更多还原