GaAs/Al_xGa_(1-x)As非对称耦合双量子阱中的激子态  

Excitonic States in Asymmetrically Coupled Double Quantum Wells of GaAs/Al_xGa_(1-x)As

作　　者：王蕊[1] 班士良[1] 

机构地区：[1]内蒙古大学物理科学与技术学院,呼和浩特010021

出　　处：《内蒙古大学学报（自然科学版）》2016年第4期374-381,共8页Journal of Inner Mongolia University：Natural Science Edition

基　　金：国家自然科学基金(批准号:61274098)资助的课题

摘　　要：考虑三元混晶效应,采用变分法计算GaAs/AlxGa1-xAs非对称耦合双量子阱中激子的结合能及其尺寸和压力效应.结果表明:由于双阱的耦合作用,激子结合能表现出与对称情形显著不同的性质,随着阱宽的非对称变化,激子类型可在直接型和间接型之间相互转化.在中间垒厚取较小的固定值时,结合能随左阱宽的增加先减小到一极小值,后增大再减小;随着中间垒厚的增加,结合能最初展现微弱震荡变化,然后突然减小.结合能随Al组分和压力影响均受双阱的耦合和对称性影响较大.A variational method is adopted to investigate the binding energies of excitons with size and pressure effects in GaAs/AlxGa1-x As asymmetrically coupled double quantum wells（ACDQWs）by considering the effect of the ternary mixed crystal.The numerical results indicate that the binding energies of excitons in the ACBQWs exhibit significantly different properties from that of symmetrically coupled double quantum wells due to the coupling effect of the double wells.The types of the excitons may change between direct and indirect ones.The binding energies decrease to a minimum then increase and finally decrease with increasing the left well width when the middle barrier thickness takes a smaller fixed value;on the other hand,as the barrier width increases,the binding energies show a slight oscillation at first,then suddenly decrease;Furthermore,the influence from Al component and pressure obviously depends on the coupling effects and the symmetry of wells.

关 键 词：非对称双量子阱 激子结合能 尺寸效应 压力效应 

分 类 号：O471.3[理学—半导体物理]