耦合GaN/Al_xGa_(1-x)N量子点中的激子特性  

Exciton Confined in GaN/Al_xGa_(1-x)N Coupled Quantum Dots

作　　者：危书义[1] 吴花蕊[1] 夏从新[1] 黄文登[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》2005年第3期190-194,共5页Chinese Journal of Liquid Crystals and Displays

基　　金：河南省教育厅自然科学基础研究计划项目(No.2003140027;2004140003);河南省高校青年骨干教师资助计划

摘　　要：在有效质量近似下,运用变分方法,考虑到量子点内电子和空穴的三维束缚以及由压电极化和自发极化所引起的内建电场,对圆柱型耦合GaN量子点的光学性质及激子态做了研究。给出了激子结合能Eb、量子点发光波长λ、电子空穴复合率和量子点高度LGaN以及势垒层厚度LAlGaN之间的函数关系。结果表明,量子点高度LGaN、势垒层厚度LAlGaN的增加将导致激子结合能、电子空穴复合率的降低,耦合量子点发光波长的增加。This paper presents a fully three-dimensional study of the exciton optical response of vertically coupled GaN-based quantum dot via a variational approach within the framework of effective-mass approximation. The strong built-in electric field due to the piezoelectricity and spontaneous polarization is considered. The relationship between exciton states and structural parameters of coupled QDs is studied in detail. The numerical results show that with the increase of the height of quantum dat (the barrier thickness),the exciton energy and electron-hole recombination rate are reduced and the quantum dot emission wavelength is increased.

关 键 词：耦合量子点 压电极化 自发极化 量子约束斯塔克效应 带间光跃迁 

分 类 号：O472[理学—半导体物理]