应变量子阱能带偏置的分析与计算

Analysis and Computation of Band Offset of Strained Quantum Wells

利用Model-solid及Harrison两种模型计算不同势垒材料的InGaAs量子阱的能带偏置比,选择出适合于计算InGaAs量子阱能带偏置比的模型是Model-solid模型。讨论了引入应变、量子阱材料组分、势垒材料组分和禁带宽度对能带偏置的影响。结果表明,压应变的引入会增大禁带宽度,减小能带偏置;随着势阱材料组分和势垒材料组分的增加,能带偏置会逐渐增大,但能带偏置比并非一直随势垒材料组分的增加而增大;InxGa1-xAs/AlyGa1-yAs量子阱的Al含量y约为0.1是较佳值,In含量x小于0.2是较佳值。

We calculate the band offset ratio of InGaAs quantum wells with different barrier materials using Modelsolid theory and Harrison model. The Model-solid theory, which is more suitable for the studied materials, is selected to calculate the band offset ratio. Then we discuss the influence of the strain, quantum well material composition, barrier material composition and band gap, on the band offset. The results show that the compressive strain will increase the band gap and reduce the band offset. With increase of the trap material composition and barrier material composition, the band offset will gradually increase. However, the band offset ratio is not always increased with the increase of barrier material composition. In InxGa1-xAs/AlyGa1-y Asquantum wells, the Al content （y） of about 0.1 is the preferred value, and the In content （x） less than 0.2 is the preferred value.