应变自组织量子点的几何形态对应变场分布的影响

采用自组织生长应变量子点的二维轴对称模型,系统分析了量子点内部及周围材料的应变分布.分别对透镜形、圆柱形、圆锥形和金字塔形量子点的应变分布进行了比较.结果表明主应变和切应变的分布受几何形状影响比较明显,静水应变几乎不受几何形状改变的影响,无论是在中心轴路径还是量子点周边路径静水应变基本一致,中心轴路径无切向应变分量,切向应变分量主要集中在量子点的边界,但在量子点几何边界的中心无切向应变,切向应变的极值分布在几何边界的拐点处.

Influences of Differently Shaped Quantum Dots on Elastic Strain Field Distributions

Adopting the two-dimensional axis-symmetrical model,a systematic analysis of the elastic strain distribution of geometrically differently shaped quantum dots is conducted using the finite element method.The detailed results for the elastic strain distribution of lens,cylinder,pyramid,and cone-shaped quantum dots are given.These show that the shape of the quantum dot has obvious influences on both the normal and shear strain distributions,while not affecting the hydrostatic strain distributions.The hydrostatic strain distribution is almost the same in both the center axis and circumjacent path.The shear strain distributions are focused on the circumjacent path,and the extremas are located in the inflexion of the circumjacent path,while the other parts of the quantum dot,including the path along the center axis,have no shear strain.