不同形状InN/GaN量子点应变场的有限元分析

Analysis on Finite Element of Elastic Strain Field in Differently Shaped Quantum Dots

摘要:

量子点中的应变场分布对量子点的力学稳定性、压电性能以及光电性能有着重要的影响。基于有限元方法,并考虑了InN/GaN材料的六方纤锌矿结构特性,分别对透镜形、平顶六角金字塔形和六角金字塔形量子点的应变分布进行了比较,结果表明应变主要集中在浸润层和量子点内,在讨论量子点中电子能级时必须考虑浸润层的影响。量子点内的应变分布及静水应变和双轴应变受几何形状的影响明显。此外还计算了三种形状量子点的总能量,六角金字塔形量子点总能量最小,而透镜形量子点总能量最大,因此六角金字塔形是最稳定的结构,而透镜形是最不稳定的结构。

Abstract:

The strain field distributions have important impacts on mechanical stability,piezoelectric effect and photoelectric effect of quantum dots.Based on the finite element approach,and considering the wurtzite structure of InN and GaN,investigated are the strain field distributions of lens,flattened hexagonal pyramid and hexagonal pyramid-shaped quantum dots.The results show that the strain field distributions are focused in quantum dots and wetting layer,so it should be noticed that the wetting layer has an ef...