各向异性对InAs/GaAs量子点应变分布的影响

研究了InGaAs/GaAs自组织量子点体系的应变分布.结果表明, 量子点形状的各向异性对其流体静压应变的影响较为微弱, 而对单轴应变的影响则更加明显且较为复杂.对于实验生长的常见S-K模式的量子点, 其弹性张量的立方对称度大于形状对称度, 因此应变分布中的各向异性主要由量子点形状的各向异性决定.量子点内部应变对于量子点各方向尺寸的相对变化较为敏感, 而量子点体积的变化对其应变分量几乎没有影响.

Effect of Geometrical Symmetry on Strain Distribution of InGaAs/GaAs Self-Organized Quantum Dots

The strain distribution of InGaAs/GaAs self-organized quantum dots(QDs)is investigated.The influence of the QDs'geometrical symmetry on hydrostatic strain is relatively weak, while on uniaxial strain is more obvious and complex.For the Common Stranski-Krastanov growth mode, the cubic symmetry of elastic tensor is larger than that of shape, so the anisotropic strain distribution in QDs is mainly affected by the geometry anisotropy.The internal strain is more sensitive to the changes in size in different directions, while for the volume changes of QDs, the strain component is almost unaffected.