摘要
在有效质量近似和变分原理的基础上,选取三个不同的变分波函数,研究了纤锌矿结构的GaN/AlxGa1-xN柱形量子点中类氢施主杂质态结合能随量子点高度L及杂质位置z0、ρ0的变化规律。计算结果表明:三个不同变分波函数计算得到的杂质态结合能随量子点高度L及施主杂质位置z0、ρ0的变化规律一致,但对比三个不同变分波函数计算所得结果可知,选取单参量的各向同性类氢波函数,杂质态结合能最大,基态能最低,按变分原理,表明各向同性类氢波函数能更好地描写柱形量子点中类氢施主杂质电子的运动,也表明小量子点(量子点的直径和高度可比)中类氢施主杂质态一定程度上的各向同性行为。
Based on the framework of effective-mass approximation and variational approach,the binding energy of a hydrogenic donor impurity state is investigated theoretically as functions of the quantum dot height and the impurity position by employing three different variational wave functions for a cylindrical wurtzite GaN/AlxGa1-xN quantum dot（QD） with finite potential barriers.The numerical results show that the variational law of the donor binding energy with the quantum dot height（L） and the impurity position（z0 and ρ0） is agreement by using variational calculations forthree different trial wave functions.It is seen that the donor binding energy is highest and the ground-state energy is lowest among the energies using the isotropic hydrogenic wave function φ1 with a single parameter in comparison with the results given by three different trial wave functions.It is shown that the isotropic hydrogenic wave function φ1 can describe better the internal motion of hydrogenic donor impurity to electron in the cylindrical QD according to the variational approach.On the other hand,φ1 performs better in the small QDs（with the diameters of the QDs comparable to the heights）,again indicating a ratherisotropic behaviorof the impurity state.
出处
《三明学院学报》
2010年第4期309-313,共5页
Journal of Sanming University
基金
福建省教育厅科技项目(JK2009038)
三明学院科学研究发展基金项目(B0820/G)
关键词
柱形量子点
类氢施主杂质态
波函数
cylindrical quantum dot
hydrogenic donorimpurity
wave function
