摘要
本文报道弹性应变及结构参数对 InAs/GaAs应变层超晶格导带、价带不连续性及其子能带结构的影响.通过分析流体静应力和单轴应力对体材料带边能带位置的影响,确定了 InAs/GaAs超晶格导带及价带能量不连续性,并用包络函数法计算了该超晶格的子能带结构.结果表明:这些量不仅依赖于组成超晶格的两种材料的体性质,而且还依赖于超晶格的晶格常数,势阱、势垒宽度以及材料的应变;通过调节InAs层与 GaAs层的层厚之比,可以使 InAs/GaAs超晶格价带轻空穴处于第Ⅱ类超晶格势当中,从而实现轻空穴与电子、重空穴的空间分离.
Results concerning the effects of elastic strain and structural parameters on the band struc-tures for InAs/GaAs strained-layer superlattices(SLS's) are presented. By analyzing the influen-ce of the hydrostatic strain and uniaxial srain on the band edges of the host materials, wehave determined the band lineups of InAs/GaAs SLS's, and calculated their corresponding sub-band energies using the envelope-function approximation. It is shown that these quantities aredependent not only on the bulk properties of the host materials, but also on the superlatticelattice constant, layer thickness and strain of individual layer, and a quasi-type-Ⅱ InAs/GaAssuperlattice can be obtained by adjusting the ratio of the thickness of InAs to that of GaAs.
