量子点光跃迁性质的研究

Study on Optical Transition Property of Semiconductor Quantum Dots

针对半导体量子点中电子的光跃迁性质进行了研究 ,建立起盘形量子点模型 ,具体分析了该模型的电子结构和电子态 .讨论了光场作用下 ,量子点中电子的跃迁几率、跃迁频率、选择定则和能级结构 ,并给出了吸收系数α的解析表达式和相应的吸收曲线 .最后 ,还讨论了量子点光跃迁性质对尺寸的依赖性以及此模型的一维、二维过渡 .结果表明 ,当束缚增强 ,能级随半径变小而增高 ,能级差变大 ;而且 ,吸收峰随尺寸减小向短波方向移动 。

The optical transition property of semiconductor quantum dots is studied. A model for disk shape quantum dots and its electronic state are given. In the incidental light, the transition matrix element, transition probability and frequency, the selection rule, the energy level structure are discussed step by step. Sequentially, the graphic of the absorption coefficient is offered. Lastly, the size dependence of optical transition property in quantum dots is analyzed. The results show that the energy and the energy difference increase with decreasing of the radium. In addition, the absorption peak will move toward the short wavelength with decreasing of the size of quantum dot.