球型核壳量子点结构中二类激子向一类激子的转化

王志平; 邢 雁; 王 旭

doi:null

您当前的位置：

首页 >

文章列表页 >

球型核壳量子点结构中二类激子向一类激子的转化

论文 | 更新时间：2020-08-12

- 球型核壳量子点结构中二类激子向一类激子的转化
- Transformation from Type- Ⅱ to Type- Ⅰ Excitons in Spherical Core-shell Quantum Dots
- 发光学报 2009年30卷第4期页码：453-456
- 作者机构：
  
  内蒙古大学物理科学与技术学院,内蒙古呼和浩特,010021
- 作者简介：
- 基金信息：
- DOI：
  中图分类号： O472.3;O469
- 纸质出版日期：2009-8-30，
  
  网络出版日期：2009-8-30，
  
  收稿日期：2008-12-7，
  
  修回日期：1900-1-2，
扫描看全文
王志平, 邢雁, 王旭. 球型核壳量子点结构中二类激子向一类激子的转化[J]. 发光学报, 2009,30(4):453-456.

WANG Zhi-ping, XING Yan, WANG Xu. Transformation from Type- Ⅱ to Type- Ⅰ Excitons in Spherical Core-shell Quantum Dots[J]. Chinese Journal of Luminescence, 2009,30(4):453-456.
王志平, 邢雁, 王旭. 球型核壳量子点结构中二类激子向一类激子的转化[J]. 发光学报, 2009,30(4):453-456. DOI：

WANG Zhi-ping, XING Yan, WANG Xu. Transformation from Type- Ⅱ to Type- Ⅰ Excitons in Spherical Core-shell Quantum Dots[J]. Chinese Journal of Luminescence, 2009,30(4):453-456. DOI：

摘要

在有效质量近似下

采用变分方法研究了球型核壳量子点中激子的性质。数值计算了电子波函数随位置的变化关系以及临界势随球壳宽度和核半径的比值的变化关系。结果表明

当球壳宽度和核半径的比值为给定值时

存在一临界势

当局域势减小到临界势时

激子从二类激子转化为一类激子;当局域势为给定值时

存在一临界比值

当球壳宽度和核半径的比值减小到临界比值时

激子亦从二类激子转化为一类激子。该结果对研究球型核壳量子点中的电子结构有参考价值。

Abstract

The excitons in the spherical semiconductor core-shell quantum dots embedded in an insulator matrix were studied theoretically in a simplified model within the framework of effective mass approximation by using the variational approach. The calculations for the values of the wave functions as functions of coordinate

and the critical potential as functions of the ratio of shell width to core radius were performed numerically

respectively. It was found that there exists a critical potential for a given ratio of the shell width to core radius

when the potential decreases cross this critical value the exciton transforms from a type- Ⅱ exciton into a type- Ⅰ exciton. For a given potential

there exists a critical ratio of the shell width to core radius

when this ratio decreases cross this critical value the exciton transforms from a type- Ⅱ exciton into a type- Ⅰ exciton. The essential features were clarified

which may serve as a starting point for the analysis of excitons in real materials.

关键词

激子量子点变分法

Keywords

excitonquantum dotvariational approach

references

. Hines M A, Guyot-Sionnest P. Synthesis and characterization of strongly luminescing ZnS-capped CdSe nanocrystals [J]. J. Phys. Chem., 1996, 100 (2):468-471.

. Peng X, Schlamp M C, Kadavanich A V, et al. Epitaxial growth of highly luminescent CdSe/CdS core/shell nanocrystals with photostability and electronic accessibility [J]. J. Am. Chem. Soc., 1997, 119 (30):7019-7029.

. Schlamp M C, Peng X, Alvisatos A P. Improved efficiencies in light emitting diodes made with CdSe(CdS) core/shell type nanocrystals and a semiconducting polymer [J]. J. Appl. Phys., 1997, 82 (11):5837-5842.

. Cao Y W, Banin U. Synthesis and characterization of InAs/InP and InAs/CdSe core/shell nanocrystals [J]. Angew Chem. Int. Ed., 1999, 38 (24):3692-3694.

. Hu Xuebing, Zheng Zhuhong, Gong Weiwei, et al. Photoluminescence of self-assembled CdSe quantum dots with different thickness CdSe quantum well layers [J]. Chin. J. Lumin. (发光学报), 2007, 28 (5):724-729 (in Chinese).

. Rorison J M. Excitons in type- Ⅱ quantum-dot systems: a comparison of the GaAs/AlAs and InAs/GaSb systems [J]. Phys. Rev. B, 1993, 48 (7):4643-4649.

. Laheld U E H, Pedersen F B, Hemmer P C. Excitons in type- Ⅱ quantum dots: binding of spatially separated electron and hole [J]. Phys. Rev. B, 1993, 48 (7):4659-4665.

. Schooss D, Mews A, Eychmüller A, et al. Quantum-dot quantum well CdS/HgS/CdS: Theory and experiment [J]. Phys. Rev. B, 1994, 49 (24):17072-17078.

. Pokatilov E P, Fonoberov V A, Fomin V M, et al. Electron and hole states in quantum dot quantum wells within a spherical eight-band model [J]. Phys. Rev. B, 2001, 64 (24):245329-1-7.

. Ivanov S A, Nanda J, Piryatinski A, et al. Light amplification using inverted core/shell nanocrystals: towards lasing in the single-exciton regime [J]. J. Phys. Chem. B, 2004, 108 (30):10625-10630.

. Piryatinski A, Ivanov S A, Tretiak S, et al. Effect of quantum and dielectric confinement on the exciton-exciton interaction energy in Type II core/shell semiconductor nanocrystals [J]. Nano. Lett., 2007, 7 (1):108-115.

. Pokrant S, Whaley K B. Tight-binding studies of surface effects on electronic structure of CdSe nanocrystals: the role of organic ligands, surface reconstruction, and inorganic capping shells [J]. Eur. Phys. J. D, 1999, 6 (2):255-267.

. Li J, Wang L W. First principle study of core/shell structure quantum dots [J]. Appl. Phys. Lett., 2004, 84 (18):3648-3650.

. Larsson M, Holtz P O, Elfving A, et al. Reversed quantum-confined Stark effect and an asymmetric band alignment observed for type- Ⅱ Si/Ge quantum dots [J]. Phys. Rev. B, 2005, 71 (11):113301-1-4.

. Bartnik A C, Wise F W, Kigel A, et al. Electronic structure of PbSe/PbS core-shell quantum dots [J]. Phys. Rev. B, 2007, 75 (24):245424-1-6.

浏览量

下载量

CSCD

文章被引用时，请邮件提醒。

提交

工具集

关联资源

电场调控下不对称耦合量子点中激子的发光特性

抛物量子点中弱耦合激子的光学声子平均数

量子点中磁激子的极化子效应

半导体量子点中弱耦合激子的性质

红外波段超辐射发光二极管研究进展