在有效质量理论的框架内,使用B样条方法,分别计算得到了球冠状InAs自组织量子点的高度和底面半径对电子能级的影响关系,且与实验结果和其他理论方法计算的结果进行了比较.结果表明:当量子点高度增大时(从1 nm到10 nm),其能级降低,能级间距减小.与底面半径对电子能级的影响相比,量子点高度是影响电子能级的关键因素,尤其是对基态能级几乎有决定性作用.同时,计算过程及结果也证明B样条方法在计算球冠状量子点电子能级方面是行之有效的.
The dependence of the electronic energy levels of self-assembled quantum dots in shape of spherical lens on the height h and radius s at the base is studied respectively. Within the framework of the effective-mass theory and envelope function, the correlation between electronic energy levels and the sizes of quantum dots is obtained by expanding wave function with B-spline basis. It can be seen from the results that the energy levels lower and the energy separations decreases with volume of SAQD increased. And compared with the effect of radius, the height of quantum dot dominates the energy levels in lens-shape SAQD, especially the ground-state level. Our results are also compared with those obtained from other calculations and experiment. In addition, the B-spline technique is proved to be a practical and convenient method in calculation the electronic energy levels in SAQD since the boundary conditions can be easily satisfied without complex calculations by employing the suitable knot sequence.