【摘要】 在紧束缚近似下,本文首次采用Recursion方法,对（AlAs）_n/（GaAs）_n（n≤10）短周期超晶格的表面、界面和体内电子结构进行了详细计算.给出了它的总态密度（TDOS）、局部态密度（LDOS）和分波态密度（PDOS）.由此证明了界面的影响,并得到了Al,Ga和As原子的原子价.超晶格有序势使（AIAs）_n/（GaAs）_n的直接带隙变窄,这表明了它与无序合金Al_xGa_1-xAs之间物理性质的差别.同时直接证实了（001）表面原子的成键方式将引起退杂化SP₂+P_γ-P_y发生.本文结论优于已有的理论报道,并与最近的实验数据符合很好.更多还原

【Abstract】 Based on tight-binding approximation(TBA), we have calculated the surface, Interface and bulk electronic structures of short-period (AlAs)n/(GaAs)n (n≤10) superlattices using Recursion method, The densities of states of total(TDOS), the local(LDOS), and the partial wave(PDOS) ara shown respectively. The influence of interface on the bulk DOS is discussed. We also give the valence for Al, Ga and As atoms in this material. Because of the ordered potential,the direct band gap of (AlAs)n/ (GaAs)n superlattices becomes narrower, which shows the different physical properties of this ultrathin layers and AlxGa1-x As alloy. At the same time we have proved that the dehybrid at (001) surface is SPZ+Px-P4·Our results are better than the former theoretical reports and in good agreement with recent experiments.更多还原