在有效质量近似和变分原理的基础上,考虑量子点的三维约束效应和内建电场,研究了ZnO/MgxZn1-xO耦合量子点中激子结合能、带间光跃迁能以及电子-空穴复合率随量子点结构参数(量子点高度和势垒层厚度)的变化。结果表明:激子结合能、带间光跃迁能和电子-空穴复合率随量子点高度或势垒层厚度的增加而降低。
Within the framework of the effective-mass approximation, this paper presents a three-dimensional study of the exciton in ZnO/MgxZn1-xO vertically coupled quantum dots (QDs) by a variational approach. The strong built-in electric field due to the piezoelectricity and spontaneous polarization is considered. Our numerical results show that the exciton binding energy, the QD transition energy and the electron-hole recombination rate are reduced monotonically when the dot height and the barrier thickness between the coupled wurtzite ZnO QDs are increased.