应变量子阱能带结构的数值分析

 以InGaAs/GaAs应变量子阱材料为例,讨论了量子阱结构中的应变效应,用k·p微扰理论给出包括重空穴带、轻空穴带和自旋-轨道分裂带相互作用和考虑应变作用的6×6 Luttinger-Kohn哈密顿量,利用Matlab精确求解,并进行数值模拟得到了布里渊区中心的导带结构、价带结构和包络函数。结果表明,应变的引入使晶体产生畸变,改变了晶体结构的对称性,进而改变了材料的能带结构,提供了一种有效的能带裁剪手段。特点是将带隙、带边偏置比和能带结构计算系统结合起来,构成一个完整体系,该模型同样适用于其他III-V族的半导体量子阱的能带结构。

Numerical Analysis on the Band Structure of Strained Quantum Wells

Taking strained quantum wells of InGaAs/GaAs as an example, the strain effect in the quantum well structure is discussed. Based on the k·p perturbation theory, the 6×6 Luttinger-Kohn Hamiltonian which include the heavy hole band, light hole band, the split-orbit splitting band mixing effect and strain effect is given. The 6×6 Luttinger-Kohn Hamiltonian is exactly calculated by using Matlab, with the numerical simulation, the conduction band structure, the valence band structure, and the envelope function at the center on Brillouin zone are obtained. The results indicate that introducing the strain makes the crystal distort, the symmetry of the crystal structure change, and furthermore the band structure of the material change, providing an effective band cutting tool. The research work is characterized as follows: a complete system model which considers all the effects, involving the band-gap, the band offset, and the band structure, is establish. The model is also suitable to calculation the band structures of other Ⅲ-Ⅴfamily semiconductor quantum wells.