半导体量子点中极化子的跃迁能量  

Transition Energy of Polaron in Semiconductor Quantum Dot

作　　者：张鹏[1] 王慧[1] 赵昆[1] 肖景林[2] 

机构地区：[1]中国石油大学(北京)数理系,北京102249 [2]内蒙古民族大学物理与机电学院,内蒙古通辽028043

出　　处：《发光学报》2009年第4期525-528,共4页Chinese Journal of Luminescence

基　　金：国家自然科学基金(10347004;60778034);教育部新世纪优秀人才支持计划(NCET-08-0841);中国石油天然气集团公司中青年创新基金(CNPC2006);中国石油大学(北京)校长基金(2005)资助项目

摘　　要：研究了半导体量子点中极化子的激发态性质。采用Huybrechts线性组合算符和幺正变换方法,计算了量子点中极化子的振动频率、基态能量、第一激发态能量、由第一激发态向基态的跃迁能量和跃迁频率。分别讨论了电子-LO声子在强弱两种耦合情况下极化子的跃迁能量和跃迁频率。数值计算结果表明,跃迁能量ΔE和跃迁频率ω均随量子点有效受限长度l0的增加而减少,且随电子-声子耦合强度α的增加而减少。In recent years, with the development of semiconductor growth technology, people have produced- some kinds of quantum dots. The novel optoelectronic properties and the transport characteristics of quantum dots will be a widely applied prospect. The interaction of of the electrons with longitudinal-optical （LO） phonons in quantum dot have attracted more physicists because of the electronic properties of particular importance. The more physicists have studied the polaron in quantum dots by a lot of method. The properties of bound polaron in a parabolic quantum dot have been discussed using the linear combination operator and the unitary transformation method by the present authors. However, using Huybrechts＇ method, the properties of the excited state of polaron in a quantum dot has not been investigated so far. In this paper, the ground-state energy, the first excited-state-energy,the transition energy from first excitedstate to ground-state and transition frequency were derived by using the Huybrechts＇ method. Two limiting cases were discussed. Firstly, we investigated the transition energy and the transition frequency of the weakcoupling polaron in a semiconductor quantum dot. The numerical results showed that the transition energy and the transition frequency increases with decreasing the effective confinement length. Secondly, we investigated the transition energy and the transition frequency of the strong-coupling polaron in a semiconductor quantum dot. The numerical results showed that the transition energy and the transition frequency increases with decreasing the effective confinement length of quantum dot . The transition energy and the transition frequency of weak-and strong-coupling polaron in a semiconductor quantum dot decreases with increasing the electron- phonon coupling strength.

关 键 词：量子点 极化子 跃迁能量 跃迁频率 

分 类 号：O469[理学—凝聚态物理] O472.3[理学—电子物理学]