关键词: 应变减少层;量子点;电子结构

Abstract: A systematical investigation about the strain distributions around the InAs/GaAs quantum dots using the finite element method is presented. A special attention is paid to the influence of In0.2Ga0.8As strain reducing layer. The numerical results show that the horizontal and vertical strains components are reinforced in the InAs quantum dot due to the strain reducing layer. The hydrostatic strain and biaxial strain, which are significant to the electronic structure, are also increased in the quantum dot. In the framework of eight-band k·p theory, we studied the band edge modification in the presence of strain reducing layer. Results demonstrate that the strain reducing layer yield the decreasing of band gap, I. E. ,the redshift phenomenon observed in experiment. Our calculated results show that the degree of the redshift will increase with increasing the thickness of the strain reducing layer. The calculated results can explain the experiment results in literature, and further confirmed that the long wavelength emission used for optical fiber communications are realizable by adjusting the dependent parameters.