类氢杂质对InxGa1-xN/GaN和GaN/AlxGa1-xN量子点中束缚激子态的影响Effects of Hydrogenic Impurity on Bound Exciton States in InxGa1-xN/GaN and GaN/AlxGa1-xN Quantum Dots
赵玉岭,戴宪起
摘要(Abstract):
在考虑内建电场效应和量子点(QD)的三维约束效应的情况下,运用变分方法研究了类氢施主杂质的位置对Ⅲ族氮化物量子点中束缚激子态的影响.结果表明:当类氢施主杂质位于量子点中心,InxGa1-xN/GaN量子点的高度和In含量大于临界值时,约束在QD中激子的基态能降低,激子态的稳定性增强,在较高的温度下观察到半导体量子点吸收谱中的激子峰,发光波长增大.而类氢施主杂质总是使束缚在GaN/AlxGa1-xN量子点中激子的基态能降低,杂质可能使在更高温度下观察到GaN/AlxGa1-xN量子点中的激子,发光波长增大.研究发现类氢施主杂质位于量子点上界面时,激子的基态能最小,系统最稳定;随着施主杂质下移,激子基态能增加,激子的解离温度下降,发光波长减小.
关键词(KeyWords): 类氢施主杂质;量子点;束缚激子;激子基态能;发光波长
基金项目(Foundation): 国家自然科学基金资助项目,编号60476047;; 河南省高校科技创新人才支持计划,编号2008HASTLT030
作者(Author): 赵玉岭,戴宪起
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