GaAs/AlGaAs量子阱中电子浓度的自洽计算

应用波函数展开方法,自洽计算了调制掺杂AlGaAs/GaAs/AlGaAs量子阱中电势能分布、子能级位置、2DEG浓度分布和2DEG面浓度n_s,以及这些参数与量子阱宽度、不掺杂AlGaAs厚度等材料参数的关系.计算表明,量子阱中2DEG n_s比单异质结n_s大2倍左右,量子阱宽度在200-300A之间n_s有个最大值;量子阱太宽时,2DEG主要集中在两边异质结界面附近,变为双异质结.

Self-Consistent Calculation of Electron Concentrations in GaAs/AlGaAs Quantum Well

The potential energy function,subband level, 2DEG concentration distribution and sheetdensity n, in modulation doped AlGaAs/GaAs/AlGaAs quantum well are self-consistently cal-culated using the method of wave function expansion.The relationship between these parame-ters and material parameters such as the quantum well width and the thickness of undoped Al-GaAs layer are also presented.The calculated results show that 2DEG n_2 in quantum well isapproximately twice as high as that in single-heterojunction,a maximum n_5 is obtained at qu-antum well width of 200-300A and 2DEG accumulates near the both sides of heterojunctioninterface when the quantum well width is higher than 500A.In the later case, the quantumwell becomes the double-heterojunction systems.