This paper presents a detailed analysis of the dependence of degree of strain relaxation of the self-organized InAs/GaAs quantum dot on the geometrical parameters. Differently shaped quantum dots arranged with differe...This paper presents a detailed analysis of the dependence of degree of strain relaxation of the self-organized InAs/GaAs quantum dot on the geometrical parameters. Differently shaped quantum dots arranged with different transverse periods are simulated in this analysis. It investigates the total residual strain energy that stored in the quantum dot and the substrate for all kinds of quantum dots with the same volume, as well as the dependence on both the aspect ratio and transverse period. The calculated results show that when the transverse period is larger than two times the base of the quantum dots, the influence of transverse periods can be ignored. The larger aspect ratio will lead more efficient strain relaxation. The larger angle between the faces and the substrate will lead more efficient strain relaxation. The obtained results can help to understand the shape transition mechanism during the epitaxial growth from the viewpoint of energy, because the strain relaxation is the main driving force of the quantum dot＇s self-organization.展开更多
用 PL谱测试研究了 Ga As和不同 In组份 Inx Ga1 - x As(x=0 .1,0 .2 ,0 .3)覆盖层对分子束外延生长的 In As/Ga As自组织量子点发光特性的影响 .用 Inx Ga1 - x As外延层覆盖 In As/ Ga As量子点 ,比用 Ga As做覆盖层其发光峰能量向低...用 PL谱测试研究了 Ga As和不同 In组份 Inx Ga1 - x As(x=0 .1,0 .2 ,0 .3)覆盖层对分子束外延生长的 In As/Ga As自组织量子点发光特性的影响 .用 Inx Ga1 - x As外延层覆盖 In As/ Ga As量子点 ,比用 Ga As做覆盖层其发光峰能量向低能端移动 ,发光峰半高宽变窄 ,量子点发光峰能量随温度的红移幅度变小 .理论计算证实这是由于覆盖层 Inx Ga1 - x As减小了 In As表面应力导致发光峰红移 ,而 In元素有效抑制了 In As/ Ga As界面组份的混杂 ,量子点的均匀性得到改善 ,PL 谱半高宽变窄 .用 In Ga As覆盖的 In0 .5 Ga0 .5 As/ Ga As自组织量子点实现了 1.3μm发光 ,室温下 PL谱半高宽为 19.2 me V。展开更多
基金supported by the National "973" Basic Research Program of China (Grant No 2003CB314901)the National NaturalScience Foundation of China (Grant No 60644004)the 111 Project of China (High School Innovation and Introducing Intellect Project of China) (Grant No B07005)
文摘This paper presents a detailed analysis of the dependence of degree of strain relaxation of the self-organized InAs/GaAs quantum dot on the geometrical parameters. Differently shaped quantum dots arranged with different transverse periods are simulated in this analysis. It investigates the total residual strain energy that stored in the quantum dot and the substrate for all kinds of quantum dots with the same volume, as well as the dependence on both the aspect ratio and transverse period. The calculated results show that when the transverse period is larger than two times the base of the quantum dots, the influence of transverse periods can be ignored. The larger aspect ratio will lead more efficient strain relaxation. The larger angle between the faces and the substrate will lead more efficient strain relaxation. The obtained results can help to understand the shape transition mechanism during the epitaxial growth from the viewpoint of energy, because the strain relaxation is the main driving force of the quantum dot＇s self-organization.
文摘用 PL谱测试研究了 Ga As和不同 In组份 Inx Ga1 - x As(x=0 .1,0 .2 ,0 .3)覆盖层对分子束外延生长的 In As/Ga As自组织量子点发光特性的影响 .用 Inx Ga1 - x As外延层覆盖 In As/ Ga As量子点 ,比用 Ga As做覆盖层其发光峰能量向低能端移动 ,发光峰半高宽变窄 ,量子点发光峰能量随温度的红移幅度变小 .理论计算证实这是由于覆盖层 Inx Ga1 - x As减小了 In As表面应力导致发光峰红移 ,而 In元素有效抑制了 In As/ Ga As界面组份的混杂 ,量子点的均匀性得到改善 ,PL 谱半高宽变窄 .用 In Ga As覆盖的 In0 .5 Ga0 .5 As/ Ga As自组织量子点实现了 1.3μm发光 ,室温下 PL谱半高宽为 19.2 me V。
