GaAs/Alx Ga1-x As超晶格扩展态电子能级结构的理论研究

运用Kroning_Penney模型,研究了GaAs/AlxGa1-xAs超晶格扩展态(E>V0)的电子能级结构和带宽随超晶格的阱宽、垒宽和A1组分的变化关系,以及扩展态能量随波矢k的变化关系.计算结果表明:影响光跃迁频率的最大因素是阱宽和A1的组分,随着阱宽的增加,光跃迁频率逐渐减小,随着A1组分的增加,光跃迁频率逐渐增大;影响带宽的较大因素是阱宽和垒宽,随着阱宽和垒宽的增大,带宽逐渐减小.这些将对实验和器件设计具有指导意义.

Theoretical Study of Electronic Energy Level Structure Extended States in GaAs/AlxGa1- xAs Superlattice

In this paper,we investigated the electronic energy structure of the extended state in GaAs/Al-xGa-(1-x) supperlattice based on the general formalism of the Kronig-Penny model.The optical transitin frequency and the bandwidth as a function of the quantum well width,the barrier width and the composition percent of A1 are obtained.In addition,the relation between energy of the extended states and the wave vector k is given and discussed.Our calculated results show that the more important factors that impacts the optical transition frequency are the width of well and the composition percents of Al.The wider the well is,the smaller the optical transition frequency is.The optical transition frequency is increased by the increase of the composition percent of A1.The more factors that affect the bandwidth are the width of well and the width of barrier.The wider the well and the barrier are,the smaller the bandwideth is.The result will be helpful to the experiments and the designing of devices.