GaN/AlxGa1-xN量子点中的激子态

在有效质量近似框架内,运用变分方法,考虑内建电场效应和量子点的三维约束效应,研究了含类氢杂质的G aN/A lxG a1-xN量子点中的激子态.结果表明:量子点中心的类氢杂质使激子的基态能降低,结合能升高,Q D系统的稳定性增强,光跃迁能减小;杂质位于量子点上界面时,激子的基态能最小,结合能最大,系统最稳定;随着杂质从量子点的上界面沿着z轴移至下界面,激子基态能和光跃迁能增大,结合能减小.

Exciton States Confined in Strained GaN/AlxGa1- xN Quantum Dots

Concerning the domino effect of the built-in electric field and the three-dimension confinement,exciton states with hydrogenic-like impurity confined in GaN/AlxGa1-xN quantum dots(QDs) are studied by means of a variational approach within the framework of effective-mass approximation.The results show that when there is hydrogenic-like impurity in the center of QDs,the exciton ground-state energy and the photoluminescence energy are reduced,and the exciton binding energy and the stability of exciton state are increased.When the impurity position is on the upper interphase of QDs,the exciton ground-state energy is lowest,the exciton binding energy the highest and the stability of exciton state the strongest.As the impurity moves to lower interphase of QDs,the ground-state energy and photoluminescence energy increase,and the binding energy reduces.