耦合ZnO/Mg_xZn_(1-x)O量子点中的激子态和带间光跃迁  

Exciton States and Interband Transitions in Wurtzite ZnO/Mg_xZn_(1-x)O Coupled Quantum Dots

作　　者：危书义[1] 卫国红[1] 孙永灿[1] 赵建华[1] 

机构地区：[1]河南师范大学物理与信息工程学院,河南新乡453007

出　　处：《液晶与显示》2009年第3期340-344,共5页Chinese Journal of Liquid Crystals and Displays

基　　金：国家自然科学基金资助项目(No.60476047);河南省自然科学基金资助项目(No.0611053800)

摘　　要：在有效质量近似和变分原理的基础上,考虑量子点的三维约束效应和内建电场,研究了ZnO/MgxZn1-xO耦合量子点中激子结合能、带间光跃迁能以及电子-空穴复合率随量子点结构参数(量子点高度和势垒层厚度)的变化。结果表明:激子结合能、带间光跃迁能和电子-空穴复合率随量子点高度或势垒层厚度的增加而降低。Within the framework of the effective-mass approximation, this paper presents a three-dimensional study of the exciton in ZnO/MgxZn1-xO vertically coupled quantum dots （QDs） by a variational approach. The strong built-in electric field due to the piezoelectricity and spontaneous polarization is considered. Our numerical results show that the exciton binding energy, the QD transition energy and the electron-hole recombination rate are reduced monotonically when the dot height and the barrier thickness between the coupled wurtzite ZnO QDs are increased.

关 键 词：量子点 激子结合能 带间光跃迁能 电子-空穴复合率 

分 类 号：O472.3[理学—半导体物理]