【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.更多还原

【Abstract】 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.更多还原