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的三维约束效应,研究了In xGa1-xN/GaN应变量子点中的激子结合能随量子点结构参数和量子点中In含量x的变化规律.结果表明,随着量子点高度L和半径R的增加,结合能降低,随着量子点中In含量的增加,激子的结合能增大.对给定体积的量子点,激子结合能存在一最大值,此时电子、空穴被最有效的约束在量子点内.对不同体积的量子点,最大值的位置在量子点高度L=1.7nm附近取得.
Within the framework of effective- mass approximation, we investigate the binding energy of exciton confined in InxGa1- xN/GaN strained quantum dots by means of variational approach. The numerical results show that: (1)When the height and the radius of QDs are increased the binding energy is reduced, and when In content is increased the binding energy is also increased; (2) The exciton binding energy is sensitive to the shap of the QD for a definite volume. There is a maximum in the binding energy, where the electrons and holes are the most efficiently confined in the QDs. The maxima are obtained at L = 1.7 nm for the QDs with the different volume.
出处
《淮北煤炭师范学院学报(自然科学版)》
2005年第4期21-25,共5页
Journal of Huaibei Coal Industry Teachers College(Natural Science edition)