【摘要】 利用有效质量方法和变分原理,考虑内建电场效应和量子点(QD)的三维约束效应,研究类氢杂质对GaN/AlxGa1-xN量子点中激子态的影响.结果表明:量子点中心的类氢杂质使激子的结合能升高,基态能降低,QD系统的稳定性增强,发光波长红移.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,激子基态能增大,结合能减小,带间发光蓝移.更多还原

【Abstract】 In this paper,within the framework of effective-mass approximation,effects of hydrogenic impurity on exciton states confined in GaN/Al_xGa_1-xN quantum dots are investigated by means of a variational approach.The numerical results show that the exciton binding energy and the emission wavelength increases with introducing the impurity.The carriers are more strongly confined in the QDs.The influence of the hydrogenic impurity position on the exciton states is also investigated in the paper.The numerical results show that the carriers are more strongly confined in the quantum dot when the impurity localized at the top of the QDs.The exciton binding energy and the emission wavelength are reduced with the shift of the impurity from the top to the bottom.更多还原